WEED MANAGEMENT PLAN - City of Kelowna

POST-FIRE INVASIVE PLANT 

MANAGEMENT PLAN FOR THE CITY OF 

KELOWNA 

Prepared by: 

ECO-MATTERS CONSULTING 

Summerland, BC 

DECEMBER 2006

ACKNOWLEDGEMENTS 

Eco-Matters Consulting wishes to thank the following individuals for their contributions and assistance 

during the development of the Post-fire Invasive Plant Management Plan. 

Michelle Kam, City of Kelowna 

Fred Schaad, City of Kelowna 

Watershed and Weed Crew, City of Kelowna 

Rod Allin, City of Kelowna 

Rhoda Mueller, Central Okanagan Regional District 

Crystal Klym, Ministry of Environment 

Mark Weston, Ministry of Environment 

Chris Wood, Groundlevel Geographics 

Lally Grauer, Landowner 

All the private landowners that permitted access to their property for invasive plant inventorying and 

mapping. 

MAPS USED IN THIS DOCUMENT were produced by Chris Wood, Groundlevel Geographics. 

PHOTOGRAPHS USED IN THIS DOCUMENT were provided by Lisa Scott, Eco-Matters Consulting 

SUGGESTED CITATION 

Scott, L. and K. Robbins. Post-fire Invasive Plant Management Plan for the City of Kelowna. Consultant 

report prepared for the City of Kelowna, BC by Eco-Matters Consulting, Summerland BC. 43 pages. 

FOR MORE INFORMATION, CONTACT 

Lisa Scott, Project Manager 

Eco-Matters Consulting 

8703 Palmer Place 

Summerland, BC V0H 1Z2 

Ph: (250) 404-0115 

Fax: (250) 404-0116 

Email: lscott@vip.net 

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Post-fire Invasive Plant Management Plan for the City of Kelowna 


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EXECUTIVE SUMMARY 

In 2003, a devastating wildfire burned approximately 30,000 hectares of land on the eastside of Okanagan 

Lake. Approximately 1590 hectares of the burned landscape was within the City of Kelowna. Land 

impacted by the wildfire included a significant amount of undeveloped, natural habitat contained within 

Central Okanagan Regional District owned lands, Okanagan Mountain Provincial Park, Myra-Bellevue 

Protected Area, conservation land, ranches, hobby farms and many residential properties. 

The Okanagan Mountain Park Wildfire and its associated soil disturbances created opportunities for the 

invasion and expansion of non-native plants or weeds. Invasive plants are species that are non-native to a 

respective ecosystem under consideration and whose introduction causes, or is likely to cause, economic 

or environmental harm, or harm to human health. Uncontrolled, these species can invade new 

environments and alter the structure and function of natural and managed ecosystems. 

Following the wildfire, the necessity for effective invasive plant management (inventory, treatment, 

monitoring and research) on the fire-impacted landscape became more critical. Invasive plants thrive postfire. 

Fires release soil nutrients, increase soil exposure and reduce shade, which in turn assists in breaking 

seed dormancy and stimulating plant germination. These factors assist the regeneration of both native 

plants and invasive species. Unfortunately, invasive plants are usually among the first plants to germinate 

and are extremely competitive once established, thus limiting the ability of native and other desirable 

plants to re-establish. 

In March 2006, the City of Kelowna contracted Eco-Matters Consulting to develop a Post-Fire Invasive 

Plant Management Plan for the 2003 fire-impacted landscape within the City of Kelowna boundaries. As 

a means to develop this plan, Eco-Matters Consulting completed a comprehensive inventory of existing 

invasive plant infestations on selected private and public lands within the management area. Inventory 

methodology and results were reported in Final Report: Post-fire Invasive Plant Management Plan 

(Eco-Matters Consulting 2006). 

Inventory and mapping revealed the presence of forty-four non-native plants or weeds, including twelve 

high priority species. Priority invasive plants were identified based on the actual or potential threat posed 

to eight land management goals that were identified for the project site. These goals focus on the 

conditions the invasive plant management plan is trying to create, and deal with human values, natural 

resources and financial resources. 

The twelve priority species were designated as either A or B species, based on their occurrence and 

distribution on the landscape. Priority A species are recommended for eradication, while Priority B 

species should be contained or suppressed. A third designation of Priority C includes those species that 

currently do not occur within the management area, but exist nearby and have high potential to spread into 

the management area due to their current location, capacity to expand and modes of dispersal. A total of 

ten Priority Areas were designated based on the existence of Priority A species or a combination of 

Priority A and B species. Specific management actions are identified for each priority species and area. 

Recommended actions are identified to (a) prevent the spread and establishment of existing invasive 

plants and (b) reduce the threat of the potential invasion of new invaders within the city boundaries that 

were affected by the 2003 Okanagan Mountain Fire. 

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TABLE OF CONTENTS 

ACKNOWLEDGEMENTS......................................................................................................................... i 

1.0 INTRODUCTION ...........................................................................................................................1 

1.1 Context of Invasive Plant Management ...................................................................................................1 

1.2 Overview of Approach to Invasive Plant Management ...........................................................................1 

1.3 Background ..............................................................................................................................................2 

1.4 Terms of Reference..................................................................................................................................2 

2.0 DESCRIPTION OF THE MANAGEMENT AREA ....................................................................3 

2.1 Boundaries ...............................................................................................................................................3 

2.2 Resource Base ..........................................................................................................................................4 

3.0 LAND MANAGEMENT GOALS..................................................................................................4 

3.1 Maintain Biological Diversity..................................................................................................................4 

3.2 Prevent the Direct Mortality of Species at Risk Due to Invasive Plants..................................................4 

3.3 Protect Rangeland Resources and the Health of Livestock and Wildlife ................................................4 

3.4 Protect Timber Resources ........................................................................................................................5 

3.5 Ensure Human Health and Safety ............................................................................................................5 

3.6 Maintain Enjoyment and Accessibility for Public Recreation.................................................................5 

3.7 Preserve Scenic Beauty............................................................................................................................5 

3.8 Reduce Economic Losses.........................................................................................................................5 

4.0 INVENTORY OF INVASIVE PLANTS .......................................................................................5 

5.0 PRIORITIES FOR INVASIVE PLANT MANAGEMENT ........................................................9 

5.1 Prevention ................................................................................................................................................9 

5.2 Invasive Plant Priorities ...........................................................................................................................9 

5.3 Priority Areas ...........................................................................................................................................9 

5.3.1 Lakeshore Road....................................................................................................................11 

5.3.2 End of Lakeshore Road........................................................................................................12 

5.3.3 Lebanon Creek .....................................................................................................................13 

5.3.4 Varty Creek and Tributary ...................................................................................................14 

5.3.5 Bertram Park ........................................................................................................................15 

5.3.6 Myra Bellevue Protected Area.............................................................................................16 

5.3.7 Crawford Estates ..................................................................................................................17 

5.3.8 Common Anchusa Containment Area .................................................................................18 

5.3.9 Timberline............................................................................................................................19 

5.3.10 Tansy Ragwort .....................................................................................................................20 

6.0 INVASIVE PLANT MANAGEMENT RECOMMENDATIONS ............................................21 

6.1 Prevention ..............................................................................................................................................21 

6.2 Invasive Plant Control............................................................................................................................22 

7.0 MONITORING AND FOLLOW-UP ..........................................................................................24 

APPENDICES……………………………………………………………………………………………26

List of Tables 

Table 1: List of invasive plants identified in 2006 during the post-fire inventory 

Table 2: Categorized list of priority invasive plants within the management area 

Table 3: An overview of invasive plant recommendations for the management area 

List of Figures 

Figure 1: Project boundaries of the City of Kelowna Post-fire Invasive Plant Management Plan 

Figure 2: Priority A invasive plants located within the project area 

Figure 3: Priority B invasive plants located within the project area 

Figure 4: Lakeshore Road priority area map 

Figure 5: End of Lakeshore Road priority area map 

Figure 6: Lebanon Creek priority area map 

Figure 7: Varty Creek and tributary priority area map 

Figure 8: Bertram priority area map 

Figure 9: Myra Bellevue Protected area map 

Figure 10: Crawford Estates priority area map 

Figure 11: Common anchusa containment priority area map 

Figure 12: Timberline priority area map 

Figure 13: Tansy ragwort priority area map 

Figure 14: Recommended biological control release sites 

List of Appendices 

Appendix 1. Ministry of Forests Site and Invasive Plant Inventory Record Forms 

Appendix 2. Invasive Plant Profiles 

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1.0 INTRODUCTION 

1.1 Context of Invasive Plant Management 

In recent decades there has been a tremendous expansion of invasive plant species invading natural areas 

across British Columbia, particularly in the Okanagan valley due to the significant landscape 

modification. There is an ongoing threat to both natural and managed areas, as new invasive plants or 

weeds arrive in the Okanagan. Invasive plants create large economic losses for agriculture in both 

cropland and rangeland situations. These non-native plants often provide poorer habitat for wildlife than 

native vegetation. Uncontrolled, these species can invade new environments and alter the structure and 

function of natural ecosystems. 

Within the City of Kelowna, these factors contribute to reduced productivity of managed forests and 

agricultural lands, including ranches and vineyards, and increased management costs for utility 

companies, government agencies and conservation groups. Invasive plants also have direct impacts to 

private landowners; they reduce property values, interfere with recreation, increase fire hazard and 

decrease the aesthetic appeal of the landscape. Without efforts to contain their spread, invasive plants can 

invade new habitats at a rate of 12-14% per year. 

Invasive plants are rapidly becoming one of the most pressing issues for natural managers. Unfortunately, 

most natural areas contain many invasive plant species. In the vast majority of cases, there is not enough 

labor and money to control all the invasive plants that occur in an area. Thus, managers are forced to 

prioritize plant species and identify target areas for control activities. This plan provides a framework for 

the City of Kelowna to control those plant species that are deemed as “high priority” within the land base 

impacted by the Okanagan Mountain Wildfire of 2003. 

In this report, the term invasive indicates a plant that has moved into a habitat and reproduced so 

aggressively that is has displaced some of the original components of the vegetative community. The term 

natural areas indicates an area that is in a largely undisturbed condition and supports primarily species 

that are native to the area. 

1.2 Overview of Approach to Invasive Plant Management 

Invasive plant control is part of property management. This plan is based on the desired plant species and 

communities, rather than on simply eliminating weeds. Preventive programs are implemented to keep a 

designated management area free of species that are not yet established there but which are known to be a 

problem elsewhere in the area. Priorities are set to reduce or eradicate invasive plants that have already 

established within a management area, according to their actual and potential impacts on the land 

management goals for the land, and according to the ability to control them now versus later. Actions will 

be taken only when careful consideration indicates leaving the weed unchecked would result in more 

damage than controlling it with best available methods. 

The plan follows the seven steps to an adaptive management approach as outlined below. 

1. Invasive plant species are identified through inventories of the management area. 

2. Land management goals and invasive plant management objectives are established. 

3. Priorities are assigned to the invasive plant species and patches based on the severity of their 

impacts, while considering the ability to control them. 

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4. Methods are considered for controlling them or otherwise diminishing their impacts and, if 

necessary, re-order priorities based on likely impacts on target and non-target species. 

5. Invasive plant management plans are developed based on the information gathered during steps 

#1-4. 

6. The plan is implemented. 

7. The results of management actions are monitored and evaluated in light of invasive plant 

management objectives for the management area. This information is used to modify and improve 

management objectives, control priorities and action plans. 

The premise behind this invasive plant management approach is that a structured, logical approach to 

invasive plant management, based on the best available information, is less expensive and more effective 

than an ad-hoc approach where one deals with invasive plant problems as they arise. 

1.3 Background 

In 2003, the Okanagan Mountain Park Fire burned approximately 30,000 hectares of land within both the 

Okanagan-Similkameen and the Central Okanagan Regional Districts. Approximately 1590 hectares of 

the burned landscape was within the City of Kelowna, encompassing Regional District owned lands, 

Okanagan Mountain Provincial Park, Myra Bellevue Protected Area, conservation land, vineyards, 

orchards, ranches, hobby farms and many residential properties. 

The Okanagan Mountain Park area hosts the largest provincial infestation of tansy ragwort, a toxic plant 

that invades disturbed areas in pastures, roadsides, open forests and clear-cuts. Within BC, this plant is 

primarily a coastal species. Prior to the fire, the Okanagan Mountain Park infestation was the only known 

Interior occurrence of tansy ragwort. Other invasive plants previously known to occur within the 

management area include diffuse knapweed, common burdock, Canada thistle, bull thistle and Dalmatian 

toadflax. 

Wildfires promote the regeneration of both native and introduced species. Fires increase soil nutrients and 

exposed ground, and also reduce shade. Fires also assist in breaking seed dormancy and stimulating plant 

germination. Unfortunately, invasive plants are usually among the first plants to germinate and are 

extremely competitive once established. As a result, the natural recovery of native and desirable 

vegetation is disrupted. 

Fire-impacted landscapes are further prone to the establishment of invasive plants through post-fire soil 

disturbances, including off-road recreation, salvage logging, mushroom picking and the construction of 

fireguards. These activities may contribute the spread of existing invasive plants, while the vehicles and 

equipment engaged in these actions may inadvertently serve as pathways for the introduction of seeds of 

new invasive plants. 

Following the 2003 wildfire, the potential for tansy ragwort and other invasive plants to spread increased 

dramatically. Consequently, effective planning and the implementation of weed management actions 

becomes an even greater concern on this fire-impacted landscape. 

1.4 Terms of Reference 

Eco-Matters Consulting was contracted by the City of Kelowna in March 2006 to develop a plan to 

manage invasive plant infestations within areas affected by the 2003 Okanagan Mountain Park Fire within 

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the City of Kelowna boundaries. The goal of the Post-Fire Invasive Plant Management Plan was to 

develop a strategy to deal with the expansion of established invasive plants and potential invasion of new 

species. 

The primary objectives were to: 

• inventory existing infestations of invasive plants and natural areas that are susceptible to new 

invasions; 

• prioritize invasive plant species located within the management area; 

• identify high priority management areas; 

• develop a long-term invasive plant management plan; and 

• implement an invasive plant reduction strategy for selected priority sites during the 2006 summer. 

2.0 DESCRIPTION OF THE MANAGEMENT AREA 

2.1 Boundaries 

The management area is located on the eastside of Okanagan Lake within the City of Kelowna in the 

Central Okanagan region of British Columbia. It includes all lands within city limits that were impacted 

by the 2003 Okanagan Mountain Fire. The project site totals approximately 1590 ha. 

Figure 1: Project boundaries of the City of Kelowna Post-fire Invasive Plant Management Plan 

Project Boundary 

City of Kelowna 

November 22, 2006 

Produced by: Chris Wood 

Projection: UTM NAD83 

Scale 1:55,000 

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2.2 Resource Base 

The management area supports a combination of open forest and dense forest habitats, included within 

Okanagan Mountain Provincial Park, Myra Bellevue Protected Area, Regional District owned property, 

and conservation holdings. These natural areas provide suitable conditions for a variety of wildlife 

including Species at Risk, predominantly in the lower elevations, and winter and early spring range for 

ungulates, most notably deer. 

Additional natural areas include grassland, riparian, and forested habitats which are contained within large 

parcel private residential properties, agricultural lands (primarily vineyards) and rangeland. Vineyards are 

a large contributor to the Okanagan economy and rangelands provide grazing for cattle and horses. 

The remaining natural areas within the project site are zoned for or currently under residential 

development. 

3.0 LAND MANAGEMENT GOALS 

The following subheadings describe eight land management goals for the management area. These goals 

focus on the conditions the invasive plant management plan is trying to create, and deal with human 

values, natural resources and financial resources. 

3.1 Maintain Biological Diversity 

Invasive plants steal valuable soil and nutrient reserves from native or desirable plants. They are highly 

competitive and quick to spread and once established can out-compete native vegetation, often forming 

monocultures. Perennial species like sulphur cinquefoil are extremely competitive and have rapidly 

spread throughout grasslands of the southern interior in the last decade. Japanese knotweed quickly forms 

dense, shading monocultures and has slowly decomposing litter, which inhibits the gown of other plants 

and the germination of native seed. Invasive species are considered the second most serious factor 

responsible for the extinction of native species and loss of biodiversity, worldwide, after habitat loss. 

3.2 Prevent the Direct Mortality of Species at Risk Due to Invasive Plants 

Mortality of some threatened bat species have been observed as a direct result of bats caught in the large 

Velcro-like seed heads of common burdock. 

3.3 Protect Rangeland Resources and the Health of Livestock and Wildlife 

Invasive plants degrade livestock habitat and reduce forage production. In the southern Interior of BC, 

grassland production may be reduced by as much as 88% as a result of knapweed invasion. Some species 

are also toxic to livestock or may cause physical injury. Tansy ragwort and hound’s-tongue contain 

poisonous alkaloids that cause irreversible liver damage in wildlife and livestock. St. John’s-wort 

increases photosensitization of ungulates, increasing their vulnerability to sunburns. The barbed seeds of 

hound’s-tongue and sticky seed heads of burdock attach to wool and fur of cattle and horses, resulting in 

stress and injury to animals as well as reduced sale values and increased veterinary costs for livestock. 

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3.4 Protect Timber Resources 

Invasive plants competing with the growth of planted trees can interfere with the regeneration of timber 

harvest areas. Hound’s-tongue, tansy ragwort, Canada thistle and bull thistle are common in cut blocks. 

3.5 Ensure Human Health and Safety 

Invasive plants impact humans in several ways. Tall roadside weeds, including diffuse knapweed, 

Dalmatian toadflax, prickly lettuce, Canada thistle and mustards, reduce visibility for drivers and animals, 

which in turn increases the risk of accidents and collisions. Invasive plants can also be fire hazards, 

especially non-native grasses like cheatgrass. Several invasive plants contribute to allergies, particularly 

hay fever. 

3.6 Maintain Enjoyment and Accessibility for Public Recreation 

The burs, thorns and spikes on invasive plants like diffuse knapweed, hound’s-tongue, burdock, 

cheatgrass, common anchusa, bull thistle, Russian thistle and Canada thistle can injure or cause physical 

discomfort to recreational users. Dense stands and overgrowth of these invasive plants can also prevent 

access or hinder navigation of trails and other recreational sites. 

3.7 Preserve Scenic Beauty 

Many invasive plants are unsightly, reducing the natural beauty of the landscape. 

3.8 Reduce Economic Losses 

Invasive plants reduce property values and cost landowners time and money to control. 

4.0 INVENTORY OF INVASIVE PLANTS 

Properties within the management area were selected for inventorying based on the size of the individual 

lot and the capacity to support invasive plants. Only properties greater than 2 acres were inventoried. 

Parcels smaller than 2 acres were excluded from the inventory; most of these properties were residential 

lots and contained highly manicured landscaping with no bare ground or other areas susceptible to 

invasive plants. Assessments were conducted primarily on foot, with some roadside surveys conducted 

from vehicles. 

Point data was collected for all invasive plants classified as noxious under the Weed Control Act of BC. 

Data was collected using a Trimble Pro XR differentially correctable GPS with a TSC-1 data logger at an 

accuracy of +/- 50 cm. Each data point recorded UTM coordinates, a two-letter species code, distribution 

code and when applicable other notations of interest, including the presence of biological control agents. 

Distribution codes were based on the Ministry of Forests Site and Invasive Plant Inventory Standards 

(http://www.for.gov.bc.ca/hfp/invasive/IAP_01.htm). Refer to Appendix 1 for a copy of the record form. 

Location point data was logged at 3-second intervals each day to generate a daily track log and record nil 

data. A listing of all invasive plants located within the management area is included in Table 1 on page 6. 

Figures 2 and 3 illustrate all infestations of Priority A and B invasive plants located within the 

management area. Priority designations are further outlined in section 5.2. 

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Table 1: List of invasive plants identified in 2006 during the post-fire inventory 

Common Name Scientific Name Common Name Scientific Name 

Alfalfa Medicago sativa Japanese brome Bromus japonicus 

Baby’s breath Gypsophila paniculata Japanese knotweed Polygonum cuspidatum 

Black medic Medicago lupulina Lamb's-quarters Chenopodium album 

Broad-leaved plantain Plantago major Mullein Verbascum thapsus 

Buffalobur Solanum rostratum Oxeye daisy Chrysanthemum leucanthemum 

Bull thistle Cirsium vulgare Perennial sowthistle* Sonchus arvensis 

Canada thistle* Cirsium arvense Pineappleweed Matricaria matricariodes 

Chervil Anthriscus sp. Prickly lettuce Lactuca serriola 

Chicory Cichorium intybus Redroot pigweed Amarantus retroflexus 

Climbing nightshade Solanum dulcamara Russian thistle Salsola iberica 

Common anchusa Anchusa officinalis Scentless chamomile* Matricaria perforata 

Common burdock Arctium minus Spiny sowthistle Sonchus spp. 

Common mallow Malva neglecta Spotted knapweed* Centaurea biebersteinii 

Curled Dock Rumex crispus St. John's-wort Hypericum perforatum 

Dalmatian toadflax* Linaria dalmatica Sulphur cinquefoil Potentilla recta 

Diffuse knapweed* Centaurea diffusa Tansy ragwort* Senecio jacobaea 

Downy brome Bromus tectorum Tumble mustard Sisymbrium altissimum 

Filago Filago sp. Wild mustard Brassica kaber 

Groundsel Senecio vulgaris unknownhawkweed Hieracium spp. 

Hoary alyssum Berteroa incana Western salsify Tragopogon dubius 

Horseweed Conyza canadensis White cockle Lychnis alba 

Hound's-tongue* Cynoglossum officinale Wild buckwheat Polygonum convolvulus 

*Denotes Provincially Noxious Invasive Plant 

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Figure 2: Priority A invasive plants located within the project area. 

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Eco-Matters Consulting

Figure 3: Priority B invasive plants located within the project area. 

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5.0 PRIORITIES FOR INVASIVE PLANT MANAGEMENT 

5.1 Prevention 

Preventing the spread and establishment of invasive plants is the most important management action. The 

following measures should be considered as a means to help prevent new invasive plants from becoming 

established within the management area and existing invasive plants from spreading further within the 

management area: 

• Increase the awareness of high-priority invasive plants – identification, threats and control options; 

• Detect invasive plants early – regularly inspect roads, ditches, stream banks, trailheads, parking 

areas, and other high traffic areas for new infestations; 

• Avoid transporting invasive plant seeds and plant fragments – check gravel or fill materials before 

landscaping; check clothing, gear, pets or livestock after leaving an infested area; and inspect and 

clean maintenance or heavy equipment before entering the management area; 

• Minimize soil disturbances – restrict travel to established trails and roads; and 

• Maintain healthy, vigorous natural areas - ensure a competitive plant community and immediately 

re-vegetate disturbed, bare soils with a suitable seed mixture that provides dense, early colonization. 

Preventative actions should focus on preventing new infestations of invasive plants, including those 

currently existing within the management area, as well as those with the potential to spread into the 

management area. A listing of potential invasive plants is included in section 5.2 below. This list was 

generated based on the known proximity of these invasive plants to the management area, their capacity 

to readily expand and their modes of dispersal. 

5.2 Invasive Plant Priorities 

Priority invasive plants were identified based on the actual or potential threat posed to the management 

goals listed in Section 3, as well as the feasibility of control for each species. Each species was then 

designated for control based on the distribution with the management area. Invasive plants which were 

rare within the management area and those that have small populations should be eradicated (Priority A), 

while large populations of more commonly observed invasive plants should be contained or suppressed 

(Priority B). Several additional invasive plants are listed as Priority C. These species currently do not 

occur within the management area, but were included based on their potential to spread into the 

management area due to their current location, capacity to expand and modes of dispersal. 

Refer to Table 2 on the following page. Detailed profiles of Priority A and B species are included in 

Appendix 2. 

The remaining invasive plants, listed previously in Table 1, were not designated as priority species for 

management. These species either did not adversely affect the land management goals or were beyond a 

level of feasible control. Management should focus on prevention of these species in locations where they 

presently do not occur. 

5.3 Priority Areas 

All known occurrences of Priority A invasive plants located within the following ten priority areas are 

designated for eradication. These infestations are small and isolated. Selected infestations of Priority B 

species were also identified as priorities for control based on their isolation from larger infestations of the 

same species or their potential impact on the management goals. These locations were limited to areas 

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along corridors of dispersal, specifically roadside and creek edges. Detailed maps and descriptions for 

each of the ten priority areas have been included on the following pages. The following priority areas are 

listed in random order. 

Table 2: Categorized list of priority invasive plants within the management area 

COMMON NAME SCIENTIFIC NAME STATUS 

Priority A – Eradication within priority areas 

Common anchusa Anchusa officinalis 

Regionally Noxious – Kootenay – Boundary 

Hound's-tongue Cynoglossum officinale 

Provincially Noxious 

Japanese knotweed Polygonum cuspidatum 

Scentless chamomile Matricaria perforata 


Spotted knapweed Centaurea biebersteinii 


Tansy ragwort Senecio jacobaea 


COMMENTS 

Patchy isolated infestations within the project area 

Two patches 

One plant 

One isolated infestation 

One plant 

One isolated infestation; one historic infestation 

Priority B – Contain or Suppress 

Common burdock Arctium minus 

Dalmatian toadflax Linaria dalmatica 

Diffuse knapweed Centaurea diffusa 

Hoary alyssum Berteroa incana 

St. John's-wort Hypericum perforatum 

Sulphur cinquefoil Potentilla recta 

Regionally Noxious – Bulkley-Nechako, Cariboo, 

Columbia-Shuswap, Fraser-Fort George, Kitimat- 

Stikine, North Okanagan, Okanagan-Similkameen, 

Peace River, Thompson Nicola 



Regionally Noxious – Kootenay-Boundary 

Regionally Noxious – Columbia-Shuswap, north 

Okanagan, Okanagan-Similkameen, Thompson-Nicola 

Several dense infestations with limited distribution 

Few roadside infestations 

Several infestations within the project area 

Six isolated patches 



Priority C – Prevent Establishment (On Alert) – Currently unknown within the project area 

Brown knapweed 

Blueweed 

Common tansy 

Leafy spurge 

Meadow knapweed 

Orange hawkweed 

Puncturevine 

Purple loosestrife 

Rush skeletonweed 

Russian knapweed 

Scotch broom 

Yellow starthistle 

Centaurea jacae 

Echium vulgare 

Tanacetum vulgare 

Euphorbia esula 

Centaurea debauxii 

Hieracium aurantiacum 

Tribulus terrestris 

Lythrum salicaria 

Chondrilla juncea 

Acroptilon repens 

Cytisus scoparius 

Centaurea solstitialis 

Regionally Noxious – Cariboo, Columbia-Shuswap, 

East Kootenay, Okanagan-Similkameen, Thompson 

Nicola 

Regionally Noxious – Bulkley-Nechako, Central 

Kootenay, Columbia-Shuswap, East Kootenay, North 

Okanagan 


Regionally Noxious – Columbia-Shuswap 

Regionally Noxious – Bulkley-Nechako, Cariboo, 

Central Kootenay, Columbia-Shuswap, East Kootenay, 

Thompson-Nicola 

Regionally Noxious – Okanagan-Similkameen 


Regionally Noxious – Columbia-Shuswap 


Infestation at intersection of DeHart Rd and 

Crawford Rd 

Occurs in surrounding jurisdictions 

Occurs in surrounding jurisdictions 

Occurs in surrounding jurisdictions. A single 

infestation was located in Penticton in 2006. 

Infestation at intersection of DeHart Rd and 

Crawford Rd 

Occurs within Okanagan Mountain Provincial Park. 

Dense infestation located at Chute Lake. 

Single infestation identified along Harvey Ave. in 

2005. Common in the South Okanagan and 

Similkameen Valleys. 

Several infestations located within the Central 

Okanagan 

Common and widespread in the Vernon region 

Several infestations located within the Central 

Okanagan 

One plant located at the entrance to Myra Bellevue 

Protected Area 

Occurs within 20 km of the United States Border 

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5.3.1 Lakeshore Road 

Several infestations of common burdock were located along Lakeshore Road. These infestations are 

designated for control due to the capacity of burdock seeds to be picked up and spread along the 

transportation corridor. Infestations of hoary alyssum and common anchusa were also located along the 

road edge. These infestations were designated for control due to their isolated distribution within the 

management area. 

Figure 4: Lakeshore Road priority area map 

Priority Area 

Lakeshore Road 

Invasive Plant Inventory 


December 5, 2006 



Scale 1:55,000 

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5.3.2 End of Lakeshore Road 

This priority area includes an infestation of sulphur cinquefoil at the end of Lakeshore Drive, on the south 

side of the road within Okanagan Mountain Park. Sulphur cinquefoil was not observed at higher 

elevations within this section of the management area. It was designated a priority as a means to prevent 

the infestation from expanding beyond the road edge. 

Figure 5: End of Lakeshore Road priority area map 

Priority Area 

End of Lakeshore Road 

Invasive Plant Inventory 


December 5, 2006 



Scale 1:55,000 

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5.3.3 Lebanon Creek 

Several infestations of common burdock were observed growing adjacent to Lebanon Creek. This area 

was designated a priority area due to the capacity of burdock to spread along the creek corridor and 

invade connecting waterways. One infestation of hound’s-tongue was also located near the creek. This 

species is designated for eradication within the management area. 

Figure 6: Lebanon Creek priority area map 

Priority Area 

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5.3.4 Varty Creek and Tributary 

Varty Creek and its tributaries are located within the Cedar Creek community. Infestations of common 

burdock were identified growing within the riparian zone. Each creek crossed several private properties 

increasing the potential for spread of common burdock by humans and pets. Single infestations of both 

hound’s-tongue and Japanese knotweed were also located near these waterways. These infestations are 

designated for eradication within the management area. 

Figure 7: Varty Creek and tributary priority area map 

Priority Area 

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14

5.3.5 Bertram Park 

A few isolated burdock plants were located adjacent to the eastern property border of Bertram Park. This 

infestation was identified a priority area due to its isolation and proximity to the Okanagan Lake 

shoreline. A single large infestation of common anchusa was located at the western entrance to the park. 

This species is designated for eradication at this location within the management area. 

Figure 8: Bertram priority area map 

Priority Area 

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15

5.3.6 Myra Bellevue Protected Area 

Three isolated infestations of common anchusa and one infestation of hoary alyssum were located in the 

section of Myra Bellevue PA within the management area. These infestations were designated for 

eradication due to their limited occurrence within the Protected Area. 

Figure 9: Myra Bellevue Protected Area priority area map 

Priority Area 

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16

5.3.7 Crawford Estates 

Three infestations of hoary alyssum were located within the Crawford Estates area. Two infestations were 

located along the road edge, the third was located along the trail entrance to the Regional District property 

at the end of Canyon Falls Court. 

Figure 10: Crawford Estates priority area map 

Priority Area 

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17

5.3.8 Common Anchusa Containment Area 

A north to south common anchusa containment line was designated along Stewart Road West. Within the 

management area, only isolated infestations of common anchusa were located west of this line. These 

infestations are designated for eradication. 

On the east side of the containment line, common anchusa was readily observed growing within land 

surrounding the management area, particularly within agricultural lands in the Benvoulin area of the City. 

However, within the boundaries of the management area, common anchusa was only observed at a high 

density on the properties surrounding Gasperdone Road and Hayes Road in the northeastern section of the 

management area. Given the density and distribution of common anchusa in this area, the northernmost 

infestations are considered impracticable for control. Five additional infestations of common anchusa 

were also located within Myra Bellevue Protected Area. Although, this plant is densely distributed in the 

surrounding landscape, no other infestations of common anchusa are known to occur within the entire 

Protected Area, including parkland outside of the project boundaries. As a result, these five isolated 

infestations were designated for eradication within the Myra Bellevue PA Priority Area, even though they 

are not considered for eradication within this priority area. 

Figure 11: Common anchusa containment priority area map 

Priority Area 

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18

5.3.9 Timberline 

Isolated infestations of scentless chamomile, hoary alyssum, spotted knapweed and common anchusa 

were located in the Cedar Creek Community on a property bordering Okanagan Mountain Park. These 

species are Priority A invasive plants and are designated for eradication within the management area. 

Controlling these infestations will help to protect the parkland resource. 

Figure 12: Timberline priority area map 

Priority Area 

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19

5.3.10 Tansy Ragwort 

Tansy ragwort was only located on one property within the management area. This species is designated 

for eradication due to its limited distribution and adverse effects to the ranching industry. An additional 

infestation was located within the management area in 2005 (Rhoda Mueller, pers. comm.); however, no 

new plants were located at this site in 2006. The historic infestation is identified on the priority area map 

below, as well as the infestation identified in 2006 (in pasture adjacent to end of Ivans Road). 

Figure 13: Tansy ragwort priority area map 

Priority Area 

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20

6.0 INVASIVE PLANT MANAGEMENT RECOMMENDATIONS 

The following section provides a detailed discussion of specific prevention and control measures to 

address the management of invasive plants identified within the management area. The City of Kelowna 

is strongly encouraged to carefully consider and implement these actions, to ensure effective long-term 

management of invasive plants within the management area. An overview of the recommendations 

outlined in Sections 6 and 7 is provided in Table 3. 

6.1 Prevention 

1. Contact local nursery and landscaping outlets. Encourage managers to control invasive plants prior 

to the sale of nursery or landscaping products, including potted plants, soils, gravels and mulches. 

Most infestations of common anchusa were associated with post-fire landscaping. 

2. Include invasive plant information with packages for new landowners. Information should focus 

on identification of priority invasive plants species and should outline general preventative Best 

Management Practices. 

3. Provide recommended Best Management Practices to residential developers within the 

management area, including information for single home-builders (e.g. South Slopes Estates 

development) as well as large-scale developers (e.g. Kettle Valley). 

4. Connect with the local cattlemen’s association to notify local ranching operations about the 

presence of tansy ragwort. Include a tansy ragwort fact sheet with identifying characteristics, 

impacts (with emphasis on the direct impacts of the plant to livestock), limited distribution and 

control measures. Tansy ragwort was only identified on one site, a horse pasture. An additional 

infestation was identified in 2005 on cattle grazing lands nearby; however no plants were located 

in this area during the 2006 inventory. 

5. Encourage landowners to dispose of invasive plants properly at the landfill by including a 

reminder with the seasonal yard waste pickup notices. Invasive plants should not be composted. 

6. Encourage land managers managing property within the project area to control priority invasive 

plants on their land, including utility rights-of-way, provincial parks and protected areas, regional 

parks, timber harvest licensees, gravel pit operations, residential developments, ranches, orchards 

and farmlands. Participation of all stakeholders within the management area is necessary to obtain 

effective control of priority invasive plants. 

7. Collaborate with the local utility companies – most notably FortisBC and Terasen Gas - to 

accurately survey invasive plants along utility corridors and access routes, which commonly host 

invasive species. The City should work with these utility companies to develop Best Management 

Practices, such as checking vehicles and maintenance equipment prior to leaving infested areas, or 

discouraging trespassing by posting signage along corridors. 

8. Coordinate roadside mowing to coincide with the plant biology of priority invasive plants along 

roadsides. Plants should be mowed mid-to-late June, following bolting, but prior to seed 

production. Roadside mowing conducted after seed production contributes to additional and 

unnecessary seed spread along transportation corridors. 

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21

9. Coordinate with the Central Okanagan Regional District to provide technical advice on invasive 

plant management to private landowners. 

10. Continue to control invasive plants within priority areas, including providing a summer work crew 

to assist private landowners. This incentive will help to build partnership and cooperation amongst 

landowners. 

11. Install an invasive plant awareness sign at the access road to Okanagan Mountain Park leading off 

of Timberline Road. Utility maintenance operators and park staff frequently utilize this road. 

Vehicle traffic contributes to invasive plant spread and may introduce new weeds to the area. 

12. Coordinate with the Ministry of Forests and Range to secure biological control agents for release 

on diffuse knapweed (Larinus minutus and Cyphocleonus achates) and St. John’s-wort 

(Chrysolina sp.). 

13. Coordinate with the Ministry of Environment to install an invasive plant kiosk at the end of 

Lakeshore Drive within Okanagan Mountain Park. This provincial park is a popular recreation 

site. A kiosk at this high profile site will ensure it is observed by a significant number of 

individuals and will help to encourage a reduction of invasive plant spread through recreational 

activities. 

6.2 Invasive Plant Control 

No single management technique is ideal for all invasive plant control situations. Utilizing a combination 

of tools is required for effective control. Integrated management involves a combination of biological, 

chemical and physical control techniques, as well as preventative measures as outlined in Section 6.1. 

Species-specific techniques are tailored to exploit the weaknesses of the target invasive plant and 

designed to be practical. Control recommendations are provided for each priority species identified within 

the management area. Note these recommendations only include options appropriate based on the current 

distribution and abundance of each priority species located within the management area. For complete 

information on all available control options for each species refer to Appendix 2. Release locations for 

biocontrol agents for diffuse knapweed and St. John’s-wort are indicated in Figure 14. 

Priority A Invasive Plants 

All infestations of Priority A invasive plants located within a priority area should be eradicated. 

Infestations should be monitored to ensure plants do not re-establish. 

i. Common anchusa – physically control all plants by pulling or digging, ensuring to remove the 

taproot. If seeds are present, cut and bag flower heads before removal to ensure seeds are not 

spread further; bagged stalks should be taken to the landfill for burial. Clean equipment, vehicles 

and footwear before leaving infested areas. Monitor disturbed sites for new outbreaks, especially 

on sandy or gravelly areas. 

ii. Hound’s-tongue - Pull or dig plants ensuring that the first few inches of root are removed to 

prevent re-growth. Second year plants may be cut close to ground level after bolting, but before 

seed production. At this life stage, it is unnecessary to remove the root of hound’s-tongue. If seeds 

__________________________________________________________________________________ 



22

are present, cut and bag plants and take to the landfill for burial. Check clothing, pets and 

equipment before leaving an infested area. 

iii. Japanese knotweed - Chop stems near the base and cover them with thick, black plastic and 

mulch. Caution: Stem cutting without follow-up can increase lateral spread and stem density. 

iv. Scentless chamomile – Handpull or dig small infestations. Cut or mow before flowering to prevent 

seed production. Mowing will be effective only if stands are mowed early and often, with each 

successive mowing lower than the previous. Bag seeded stalks and take to the landfill for burial. 

v. Spotted knapweed - Handpull small infestations. Plants must be pulled for several years to deplete 

the seed bank. Cut plants in the early flower stage; plants are less likely to re-sprout if allowed to 

bolt before cutting. Bag seeded plants and take to the landfill for burial. 

vi. Tansy ragwort – Handpull small infestations. Cut plants just before flowering when root reserves 

are low, but before seed production. Bag flowering or seeded plants and take to the landfill for 

burial. 

Priority B Invasive Plants 

Priority B Invasive Plants should be eradicated within designated priority areas as a means to contain or 

limit their spread throughout the greater management area. 

i. Common burdock – Pull or dig plants ensuring that the first few inches of roots are removed to 

prevent re-growth. Second year plants may be cut close to the ground after bolting, but before seed 

production. At this life stage, it is unnecessary to remove the root of burdock. If burs are present, 

cut and bag plants and take to the landfill for burial. Check clothing, pets and equipment before 

leaving and infested area. 

ii. Dalmatian toadflax – Handpull or dig small infestations. Handpulling is most successful where 

soils are sandy and/or moist, allowing for removal of as much root as possible. Physical removal 

must be repeated annually for at least ten years to completely deplete the seed bank. Hand-cutting 

toadflax stands to ground level in spring or early summer is an effective way to eliminate seed 

production and dispersal, but it will not destroy plants. Cut and bag seeded plants and take to the 

landfill for burial. 

iii. Diffuse knapweed – Handpull small infestations. Plants must be pulled for several years to deplete 

the seed bank. Cut plant in the early flower stage; plants are less likely to re-sprout if allowed to 

bolt before cutting. Cut and bag seeded plants and take to the landfill for burial. Release biological 

control agents, Larinus minutus and Cyphocleonus achates for large dense infestations (see Figure 

14). 

iv. Hoary alyssum - Handpull or hoe small infestations. Cut or mow before flowering to prevent seed 

production. Cut and bag seeded plants and take to the landfill for burial. 

v. St. John’s-wort – Handpull or cut small infestations. Cut and bag seeded plants and take to the 

landfill for burial. Release Chrysolina beetles for large dense infestations (see Figure 14). 

__________________________________________________________________________________ 



23

vi. Sulphur cinquefoil – Hand pull infestations, ensuring that the upper portion or crown of the root 

system is removed. Mowing will not control sulphur cinquefoil. Although seed production may be 

reduced, plants develop low, bulky spreading roots when mowed and are able to send up new 

shoots. Cut and bag seeded plants and handpull small infestations. 

7.0 MONITORING AND FOLLOW-UP 

Routine monitoring of the priority invasive plants and management areas is necessary to evaluate the 

effectiveness of the invasive plant management program. If management objectives are not being met, 

control options must be modified. This section outlines the general approaches that will be used to 

evaluate the effectiveness of invasive plant management actions. 

• The priority areas identified in 2006 that contain infestations of tansy ragwort should be monitored 

annually. If new plants are located, plants should be controlled utilizing the integrated control options 

described for each species in Section 6.2. Sites should be monitored until no plants are observed for a 

minimum of five years. 

• Annual monitoring is also required for the remaining priority management areas and priority invasive 

species. Infestations should be checked at least once per year and integrated control measures should 

be applied if new plants are observed. 

• Additional follow-up is required for areas within the management area where permission was not 

granted to access the properties. No data was collected for these sites in 2006 and therefore these areas 

constitute a knowledge gap with respect to the current distribution and abundance of invasive plants 

within the entire management area. Invasive plant inventories of these properties should be conducted 

in the field season of 2007. 

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24

Figure 14: Recommended biological control release sites 

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Post-fire Invasive Plant Management Plan for the City of Kelowna Eco-Matters Consulting 

25

Table 3: An overview of invasive plant recommendations for the management area 

RECOMMENDATIONS DETAILS TIMELINE 

Preventative Measures 

Avoid transporting invasive plant seeds and plant 

fragments 

Maintain healthy, vigorous natural areas 

Inspect and clean maintenance or heavy equipment before entering the management area 

Immediately re-vegetate disturbed, bare soils with a suitable seed mixture that provides 

dense, early colonization 

Ongoing 

Ongoing 

Monitor Monitor priority areas. If new infestations are located, apply integrated control measures Annually, May to late- 

June 

Coordination & Planning 

Complete invasive plant inventory 

Enter data into provincial database. 

Encourage coordinated invasive plant control 

Increase involvement of utility companies 

Coordinate roadside mowing 

Conduct inventory on properties where permission was not granted in 2006 (landowners Summer 2007 

were non-responsive) 

All invasive plant inventory and treatment data from 2006 onwards should be entered into Winter-Spring 2007, 

the Invasive Alien Plant Program (IAPP) application 

Ongoing 

Consult with utility rights-of-way, provincial parks and protected areas, regional parks, Ongoing 

timber harvest licensees, gravel pit operations, residential developments, ranches, orchards 

and farmlands 

Encourage these companies to survey invasive plants along utility corridors, which Immediately 

commonly host invasive species; recommend they develop and adopt Best Management 

Practices 

Mowing should coincide with the plant biology of priority invasive plants along roadsides. Annually, mid-to-late 

Encourage two cuts if possible. 

June 

Awareness Measures 

Increase profile of Tansy Ragwort 

Install invasive plant awareness signs 

Reduce spread of invasive plants through 

landscaping depots 

Reduce invasive plant spread through new 

residential developments 

Communicate with the local cattlemen’s association to notify local ranching operations 

about the presence of tansy ragwort 

Install signs in two key locations: (1) at the access road to Okanagan Mountain Park 

leading off of Timberline Road and (2) at the end of Lakeshore Drive within Okanagan 

Mountain Park. 

Encourage managers to control invasive plants prior to sale of nursery or landscaping 

products, including potted plants, soils, gravels and mulches 

Provide best management plans with development permits 

Immediately 

Immediately 

Contact in Spring 2007 

As needed basis 

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26

Educate new property owners 

Provide invasive plant information with packages for new landowners within the 

management area 

Increase invasive plant awareness 

Coordinate with the Central Okanagan Regional District to provide technical advice on 

invasive plant management to private landowners 

Encourage landowners to dispose of invasive plants Include a reminder with the seasonal yard waste pickup notices 

properly at the landfill 



Seasonal 

Control Measures 

Utilize biological control 

Coordinate with the Ministry of Forests and Range to secure biological control agents for 

release on diffuse knapweed and St. John’s-wort 

Control new infestations of priority invasive plants Tansy ragwort in pasture adjacent to end of Ivans Road 

in priority areas 

Burdock, common anchusa and hoary alyssum along Lakeshore Road 

Sulphur cinquefoil at the end of Lakeshore Road 

Burdock along Lebanon Creek, Varty Creek and tributary 

Common anchusa and burdock in Bertram Regional Park 

Common anchusa and hoary alyssum in Myra Bellevue Protected Area 

Hoary alyssum in Crawford Estates 

Common anchusa, scentless chamomile, spotted knapweed and hoary alyssum on 

Timberline property 

All common anchusa infestations on the west side of the Stewart Road West containment 

line. 

Release agents in 

summer of 2007 and/or 

2008 

Annually, beginning 

June to July 2007 until 

eradicated within the 

priority area. Anticipate 

a minimum of 5 years 

to eradicate most 

species. 

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27

APPENDICES 

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28

Appendix 1. MINISTRY OF FORESTS SITE AND INVASIVE PLANT 

INVENTORY RECORD FORMS 

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29

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30

Appendix 2. INVASIVE PLANTS PROFILES 

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31

COMMON ANCHUSA 

Anchusa officinalis L. 

Family: Boraginaceae (Borage) 

Other Common Names: Common bugloss, common alkanet 

Legal Status: Regionally Noxious: Kootenay/Boundary 

Description: Biennial or perennial forb. Arises from a long taproot, 

forming a rosette of hairy, stalked, lance-shaped basal leaves in its first 

year and a single flowering stalk (30-80 cm tall) in the second year. 

Multiple stalks appear in subsequent years. Flowers are blue-purple 

arranged in slightly coiled clusters at the end of stalks. Each flower 

produces a cluster of 4 barbless nutlets. Reproduces primarily by seed. 

New shoots may also develop from root stock fragments. Introduced 

from Eurasia. 

Habitat and Range: Commonly found on dry, fertile, well-drained soils along roadsides or in dry fields and 

disturbed areas. In British Columbia, the largest infestations are known northeast of Rock Creek and east of 

Kelowna in the Rutland-Black Mountain areas. Sightings have also been reported in the south Okanagan and 

Keremeos areas. 

Distribution Within the Management Area: Infestations of common anchusa were concentrated at the eastern 

most edge of the management area. Limited infestations were also observed within Myra-Bellevue Protected Area, 

Bertram Park and on properties in the Cedar Creek community. No plants were observed between Myra-Bellevue 

Canyon and Bertram Park. 

Damage and Threats: Common anchusa invades pastures and rangelands, reducing the carrying capacity and yield 

of the land. This invasive plant is also a concern to alfalfa production as leaves become mouldy, spoiling bailed 

hay. 

INTEGRATED MANAGEMENT 

Management Objective(s): 

1. Eradicate all infestations. 

2. Prevent new introductions. 

Control Options: 

Isolated plants: Cultural/Preventative 

Small infestations ( 4 acres): Mechanical 

Cultural/Preventative: Control small infestation immediately. Pulling or digging is easiest when plants are young 

before the deep taproot has developed. If seeds are present, cut and bag flower heads before removal. Monitor 

disturbed sites, especially on sandy or gravelly areas, for new outbreaks. Clean equipment, vehicles and footwear 

before leaving an infested area. Maintaining a strong population of native perennials is the best way to prevent the 

establishment of common bugloss. 

Mechanical: Cutting or mowing before flowering will prevent seed production. Flowering stalks should be bagged 

and properly disposed of at the landfill. Do not compost. 

__________________________________________________________________________________ 32 



COMMON BURDOCK 

Arctium minus L. 

Family: Asteraceae (Sunflower) 

Other Common Names: Lesser burdock, wild burdock, bardane, wild rhubarb, 

beggars button 

Legal Status: Regionally Noxious: Bulkley-Nechako, Cariboo, Columbia- 

Shuswap, Fraser-Fort George, Kitimat-Stikine, North Okanagan, Okanagan- 

Similkameen, Peace River and Thompson-Nicola 

Description: Bushy biennial. Arises from a large fleshy taproot, forming a rosette 

of large, hairy, heart-shaped basal leaves in its first year and a much-branched 

stem (1-3 m tall) in the second year. Flowers are purple, less than 2.5 cm across in 

clusters. Reproduces by seed. Introduced from Eurasia. 

Habitat and Range: Commonly found on roadsides, ditchbanks, disturbed areas 

and pastures. It is well spread in British Columbia, primarily in riparian area with 

moist, fertile soils. 

Distribution Within the Management Area: Common burdock was only observed growing along stream banks 

and Lakeshore Drive. 

Damage and Threats: The foliage from common burdock will taint milk with a bitter taste, if eaten in large 

quantities by livestock. Burs can become tangled in animal hair and may fatally trap bats. Plants also host a 

powdery mildew and root rot. 



1. Control all new infestations of common burdock 

2. Suppress large infestations of common burdock 

3. Prevent seed production 




Cultural/Preventative: Control small infestation immediately. Plants can be pulled or dugout, ensuring that the first 

few inches of root are removed to prevent re-growth. If burs are present, cut and bag flower heads before removal. 

Check clothing, pets and equipment before leaving and infested area. Maintaining a strong population of native 

perennials is the best way to prevent the establishment of common burdock. 

Mechanical: Cutting or mowing before flowering will prevent seed production. If plants are cut in the second year, 

after bolting, but before seed production, it is unnecessary to remove the root. Flowering stalks should be bagged 


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33

DALMATIAN TOADFLAX 

Linaria genistifolia spp. dalmatica L. 

Family: Scrophulariaceae (Figwort) 

Other Common Names: Broad-leaved toadflax, wild snapdragon 

Legal Status: Provincially Noxious 

Description: Perennial forb. Arises from a complex root system, including 

horizontal roots, several meters in length, which can develop new plants. Mature 

plants are 0.6 to 1.2 m tall, with 1 to 25 vertical flowering stems. Flowers are 

bright yellow and resemble snapdragons. Reproduces by seed and vegetatively 

from roots. Introduced from Europe, likely as and ornamental plant. 

Habitat and Range: Dalmatian toadflax is widespread throughout Canada and 

the US, particularly in British Columbia, Alberta, and the northwestern US. It 

can adapt to a wide range of environmental conditions and is tolerant of low 

temperatures and coarse, textured soils. 

Distribution Within the Management Area: Dalmatian toadflax was primarily 

observed along roadsides. Plants were widely distributed throughout the 

management area. 

Damage and Threats: Dalmatian toadflax is an aggressive invader, capable of forming long-lived, dense 

infestations that can compete with native and desirable plants. 

Integrated Management 

Management Goals: 

1. Control all new infestations of Dalmatian toadflax 

2. Suppress large infestations of Dalmatian toadflax 

3. Reduce the spread of Dalmatian toadflax along transportation corridors. 



Small infestations ( 4 acres): Mechanical, Biological 

Cultural/Preventative: Control small infestation immediately. Handpulling is most successful where soils are sandy 

and/or moist, allowing for removal of as much root as possible. Physical removal must be repeated annually for at 

least ten years to completely deplete the seed bank. 

Mechanical: Hand-cutting toadflax stands to ground level in spring or early summer is an effective way to eliminate 

seed production and dispersal, but it will not destroy plants. Flowering stalks should be bagged and properly 

disposed of at the landfill. Do not compost. 

Biological: Mecinus janthinus, a black stem-boring weevil, has proven to effectively control Dalmatian toadflax. 

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34

DIFFUSE KNAPWEED 

Centaurea diffusa Lam. 


Other Common Names: Spreading knapweed, tumbleweed 


Description: Biennial to short-lived perennial forb. Highly branched upright 

stems (10-60 cm tall), arise from a single taproot. Flowers are white, 

sometimes pink, with yellowish brown spiny bracts. Reproduces entirely by 

seed. Introduced from Eurasia. 

Habitat and Range: Diffuse knapweed is found throughout British Columbia 

east of the Coast-Cascade Mountains. It occurs in pastures, along roadsides and 

disturbed areas in both rural and urban environments. 

Distribution Within the Management Area: Diffuse knapweed was one of 

the most prolific invasive plants within the management area. Infestations were 

found in large patches throughout the fire-impacted landscape, particularly 

adjacent to road edges and trails, ranging from single plants to dense, large 

monocultures. 

Damage and Threats: Diffuse knapweed quickly invades disturbed habitats, reducing biodiversity and forage for 

wildlife and livestock. 


Management objective(s): 

1. Control all new infestations of diffuse knapweed 

2. Suppress large infestations of diffuse knapweed 

3. Reduce the spread of diffuse knapweed through hitchhiking along transportation corridors. 




Cultural/Preventative: Control small infestation immediately. Handpulling is most successful when soils are moist. 

Plants must be pulled for several years to deplete the seed bank. 

Mechanical: Plants should be cut in the early flower stage; plants are less likely to re-sprout if allowed to bolt 

before cutting. Plants should be cut in the early flower stage; plants are less likely to re-sprout if allowed to bolt 

before cutting. Flowering plants should be bagged and properly disposed of at the landfill. Do not compost. 

Biological: Several insects have been released in British Columbia to control diffuse knapweed. Among the most 

successful insects are Larinus minutus, a small brown weevil that consume knapweed seed heads, and 

Cyphocleonus achates, a root-boring weevil that depletes energy reserves. 

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35

HOARY ALYSSUM 

Berteroa incana L. 

Family: Brassicaceae (Mustard) 

Other Common Names: None 

Legal Status: Regionally Noxious: Kootenay-Boundary 

Description: Biennial (rarely perennial) forb. Erect, branched stems (0.3-1.1 

m tall) arise from a slender taproot. The entire plant is covered with star 

shaped hairs. Leaves are grey. Flowers are white with deeply notched petals. 

Reproduces by seed. Introduced from Eurasia. 

Habitat and Range: Hoary alyssum is most common on dry sandy or 

gravelly soils. It occurs in south-central and southeastern British Columbia 

invading meadows, pastures, hayfields, roadsides and disturbed areas. 

Distribution Within the Management Area: Three infestations of hoary 

alyssum were identified; located at the entrance to Canyon Falls Regional 

Park, within Myra-Bellevue Protected Area and on private land in the Cedar 

Creek community. 

Damage and Threats: When consumed by horses, hoary alyssum may lead to fever, lib edema and laminitis. 




2. Prevent new introductions 




Cultural/Preventative: Control small infestation immediately. Handpulling or hoeing can be successful. Maintaining 

a strong population of native perennials is the best way to prevent the establishment of hoary alyssum. 

Mechanical: Cutting or mowing before flowering will prevent seed production. Flowering stalks should be bagged 


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36

HOUND’S-TONGUE 

Cynoglossum officinale L. 

Family: Boraginaceae (Borage) 

Other Common Names: Dog bur, gypsy flower 


Description: Biennial to short-lived perennial forb. Arises from a woody taproot, 

forming a rosette of tongue-shaped basal leaves in its first year and one to several 

branched stems (0.3-1.2 m tall) in the second year. Flowers are pinkish-purple with 

five petals. The fruit is composed of 4 nutlets, which form sticky burs at maturity. 

Reproduces entirely by seed. Introduced from Eurasia, likely as a contaminant in seed. 

Habitat and Range: Hound’s-tongue prefers disturbed areas, commonly in pastures, 

roadsides and logged forests. In BC, it occurs primarily in the southern Interior. 

Distribution Within the Management Area: Hound’s-tongue was located on two properties, both on the 

west side of the project area. 

Damage and Threats: Hound’s-tongue decreases forage on rangeland and pasture. The plant contains toxic 

alkaloids that stop liver cells from reproducing. Burs can readily stick to hair, wool and fur in animals, resulting in 

reduced sale value, stress on animals and sometimes increased medical costs. 




2. Prevent seed production 





Cultural/Preventative: Control small infestation immediately. Plants can be pulled or dugout, ensuring that the first 

few inches of root are removed to prevent re-growth. If burs are present, cut and bag flower heads before removal. 

Check clothing, pets and equipment before leaving and infested area. Maintaining a strong population of native 

perennials is the best way to prevent the establishment of common burdock. 

Mechanical: Cutting or mowing before flowering will prevent seed production. If plants are cut in the second year, 

after bolting, but before seed production, it is unnecessary to remove the root. Flowering stalks should be bagged 


Biological: The weevil, Mogulones cruciger, has been recently released in British Columbia and is showing to be 

extremely effective and fast at reducing hound’s-tongue infestations. The small grayish-brown weevil is aptly 

named cruciger for the small white cross, marked on its back. 

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37

JAPANESE KNOTWEED 

Polygonum cuspidatum 

Family: (Buckwheat) 

Other Common Names: Japanese bamboo, Mexican bamboo 

Legal Status: None 

Description: Rhizomatous, semi-woody, herbaceous perennial. 

Grows to 3 metres in height with sgreet to reddish-brown “bamboolike” 

stems. Leaves are egg-shaped, stalked, 10-15 cm long. Flowers 

are greenish to creamy-white, produced in clusters from the leaf 

axils. Reproduces primarily by root, but does produce seed. 

Introduced from eastern Asia. 

Habitat and Range: Japanese knotweed is found along roadsides 

and wetland areas. It is known in BC along roadsides and moist 

climates especially in the south-west coastal region, but also in the 

Shuswap region and the Queen Charlotte Islands. 

Distribution Within the Management Area: A single plant was identified on private property in the Cedar Creek 

community along a stream bank. 

Damage and Threats: Japanese knotweed is very competitive and difficult to control. Plants will crowd out native 

vegetation, decreasing wildlife food and fish habitat. 








Cultural/Preventative: Control small infestation immediately. Maintaining a strong population of native perennials 

is the best way to prevent the establishment Japanese knotweed. Do not compost plant fragments. 

Mechanical: Chop stems near the base and cover them with thick, black plastic and mulch. Caution: Stem cutting 

without follow-up can increase lateral spread and stem density. 

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38

SCENTLESS CHAMOMILE 

Matricaria perforata Merat 


Other Common Names: Scentless mayweed, false chamomile 


Description: Annual, biennial or sometimes perennial forb. Smooth, branched 

stems (5-100 cm tall) arise from an extensive, fibrous root system. Daisy-like 

flowers are white with yellow centers, occurring at the end of each stem. 

Reproduces by seed. Introduced from Europe. 

Habitat and Range: Scentless chamomile is found on dry shorelines, 

roadsides, fence lines, disturbed areas and perennial forage crops. It occurs in 

all of BC’s agricultural regions. 

Distribution Within the Management Area: One infestation of scentless 

chamomile was identified within the Cedar Creek community. 

Damage and Threats: Scentless chamomile can form dense stands reducing cropland and rangeland yields. It is 

unpalatable to livestock. 








Cultural/Preventative: Control small infestation immediately. Handpulling or digging must be repeated frequently 

and monitored. Maintaining a strong population of native perennials is the best way to prevent the establishment of 

scentless chamomile. 

Mechanical: Cutting or mowing before flowering will prevent seed production. Mowing will be effective only if the 

stands are mowed early and often, with each successive mowing lower than the previous one. Flowering stalks 

should be bagged and properly disposed of at the landfill. Do not compost. 

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39

SPOTTED KNAPWEED 

Centaurea biebersteinii DC. 


Other Common Names: None 


Description: Biennial to short-lived perennial forb. One or more upright stems 

(0.2-1.8 m tall) arising from a single taproot. Flowers are pinkish purple or rarely 

white, with soft black fringe on the bracts resulting in a spotted appearance. 

Reproduces entirely by seed. Introduced from Europe. 

Habitat and Range: Spotted knapweed is found throughout North America. It is 

frequent in southern British Columbia east of the Coast-Cascade Mountains. 

Spotted knapweed frequently occurs along roadsides, fields and disturbed areas. 

Distribution Within the Management Area: One plant was identified within 

the Cedar Creek community. 

Damage and Threats: Spotted knapweed is highly competitive. It can reduce or displace desirable forage plant 

species and reduce the carrying capacity for livestock and wildlife. Spotted knapweed can also cause skin irritations 

to humans. 




2. Prevent new introductions 




Cultural/Preventative: Control small infestation immediately. Handpulling is most successful when soils are moist. 

Plants must be pulled for several years to deplete the seed bank. 

Mechanical: Plants should be cut in the early flower stage; plants are less likely to re-sprout if allowed to bolt 

before cutting. Flowering plants should be bagged and properly disposed of at the landfill. Do not compost. 

Biological: Several insects have been released in British Columbia to control spotted knapweed. Among the most 

successful insects are Larinus minutus and L. obtusus, small brown weevils that consume knapweed seed heads and 

Cyphocleonus achates, a root-boring weevil that depletes energy reserves. 

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40

ST. JOHN’S-WORT 

Hypericum perforatum L. 

Family: Clusiaceae (St. John’s-wort) 

Other Common Names: Klamath weed, goatweed 

Legal Status: None 

Description: Perennial forb arising from underground runners. Stems are 

erect, multi-branched and rust coloured reaching 0.1-1.0m tall. Leaves are 

covered with transparent dots. Flowers are bright yellow with 5 petals. 

Reproduces by seed and vegetatively from roots. Introduced from Eurasia. 

Habitat and Range: St. John’s-wort occurs in scattered pockets throughout 

British Columbia with major concentrations occurring in the southern 

portions of the province, at Grand Forks and at the United States border. It is 

best adapted to dry, gravelly, or sandy soils and is commonly found on 

rangeland, pasture, and meadows as well as along roadsides and disturbed 

areas. 

Distribution Within the Management Area: St. John’s wort infestations 

were primarily located in the western side of the management area, beginning 

around Chute Lake Forest Service Road 

Damage and Threats: St. John’s-wort contains a toxin that causes skin irritation and blistering in light-coloured 

livestock when they are exposed to sunlight. In dense stands, St. John’s-wort can displace plant species and reduces 

livestock and wildlife forage. 

IN TEGRATED MANAGEMENT 


1. Control all new infestations of St.John’s-wort 

2. Suppress large infestations of St.John’s-wort 




C ultural/Preventative: Control small infestation immediately. 

Mechanical: Plants can be controlled by tillage in agricultural fields. Flowering plants should be bagged and 

properly disposed of at the landfill. Do not compost. 

Biological: Chrysolina hyperici and C. quadrigemina, metallic black beetles, have been released in British 

Columbia and have shown to effectively control populations of St. John’s-wort. 

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41

SULPHUR CINQUEFOIL 

Potentilla recta L. 

Family: Rosaceae (Rose) 

Other Common Names: Rough-fruited cinquefoil 

Legal Status: Regionally Noxious: Columbia-Shuswap, North Okanagan, 

Okanagan-Similkameen, and Thompson-Nicola 

Description: Perennial forb. One or more hairy stems (30-70 cm tall) arise from a 

large woody taproot. Leaves are divided into 5-7 hairy-toothed leaflets, each 5-10 

cm long. Flowers are pale yellow with five heart-shaped petals around a bright 

yellow center. Reproduces by seed and vegetatively from roots. Introduced from 

Eurasia. 

Habitat and Range: Sulphur cinquefoil is adapted to a wide range of soils and 

climates. It occurs throughout North America in dry to moist habitats, roadsides, 

pastures, overgrazed rangelands, and disturbed areas. It is considered a major 

concern in the Kootenay, Okanagan and Thompson agricultural reporting regions. 

Distribution Within the Management Area: Sulphur cinquefoil infestations ranged from single plants to dense, 

large monocultures. Plants were observed throughout the entire project area, except for the Provincial Park located 

at the end of lakeshore. On the ¼ section lot located south of Lakeshore Dr., sulphur cinquefoil was only located 

within approximately the first 10 meters from the road edge. The largest infestations of sulphur cinquefoil were 

located on properties bordering Gillard Forest Service Road. 

Damage and Threats: Sulphur cinquefoil is very competitive with native plants and reduces forage for livestock 

and wildlife on rangelands. 



1. Control all new infestations of sulphur cinquefoil 

2. Suppress large infestations of sulphur cinquefoil 

3. Reduce the spread of sulphur cinquefoil along transportation corridors. 




Cultural/Preventative: Control small infestation immediately. When hand pulling, the upper portion or crown of the 

root system must be removed to successfully control plants. Maintaining a strong population of native perennials is 

the best way to prevent the establishment of sulfur cinquefoil. Do not compost. 

Mechanical: Mowing will not control sulphur cinquefoil. Although seed production may be reduced, plants develop 

low, bulky spreading roots when mowed and are able to send up new shoots. 

__________________________________________________________________________________ 42 



TANSY RAGWORT 

Senecio jacobaea L. 


Other Common Names: Common ragwort 


Description: Biennial or short-lived perennial. Each plant has one or more upright 

stems (0.3-1.2 m tall). Leaves are deeply cut, giving the plant a ragged appearance. 

Daisy-like flowers are bright yellow pale yellow with five heart-shaped petals 

around a bright yellow center. Reproduces by seed. Introduced from Eurasia. 

Habitat and Range: Tansy ragwort grows in disturbed sites in pastures, hayfields, 

roadsides and clear-cuts. It is frequent in the Lower Mainland and southern 

Vancouver Island. The largest provincial infestation occurs within Okanagan 

Mountain Park. Small isolated infestations of this plant were identified in the South 

Slopes area of Kelowna in 2006. No other BC interior infestations are known. 

Distribution Within the Management Area: Less than 30 plants of tansy ragwort 

were located at one infestation. 

Damage and Threats: The entire plant contains varying concentrations of poisonous alkaloids, which cause 

irreversible liver damage in wildlife and livestock. Tansy ragwort also reduces forage production of pastures by up 

to 50%. 








Cultural/Preventative: Control small infestation immediately. Hand pulling is most effective when soils are moist. 

Maintaining a strong population of native perennials is the best way to prevent the establishment of tansy ragwort. 

Do not compost. 

Mechanical: Mowing may be utilized to prevent seed production Plants should be cut just before flowering when 

plants have low root reserves, but before seed production. Repeated mowing may increase rosette density. 

Biological: Several insects have been established in the coastal areas of British Columbia; however these insects 

have not shown to survive in the Interior, likely due to the colder winter temperatures. A Maritime strain of 

Longitarsus jacobaeae is currently being trialed. 

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43

WEED MANAGEMENT PLAN - City of Kelowna

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