A guide to Lawn Grass Development for temperate - DoFPS

GREENING BHUTAN
A guide to Lawn Grass Development in Bhutan
“An Experience in cool temperate environment”
Tsering Gyeltshen
Rangeland and Farming Systems Section
Watershed Management Division
Department of Forests & Park Services
Ministry of Agriculture & Forests
Thimphu : Bhutan
December 2010

CONTENTS
1. Background .................................................................................................................. 3
2. Benefits ........................................................................................................................ 3
3. New Lawn Establishment ............................................................................................ 4
4. Planning ....................................................................................................................... 4
5. Soil preparation............................................................................................................ 5
6. Seed rate and sowing time ........................................................................................... 5
7. Rake and roll ................................................................................................................ 6
8. Watering ...................................................................................................................... 6
9. Mowing and mower ..................................................................................................... 7
10. Use of grass clippings .............................................................................................. 8
11. Lawn maintenance ................................................................................................... 8
11.1. Weeding ............................................................................................................ 8
11.2. Top-dressing ..................................................................................................... 9
11.3. Lawn Renovation .............................................................................................. 9
12. Cool season grass ..................................................................................................... 9
12.1. Lawn seed sources .......................................................................................... 10
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1. Background
A guide to Lawn Grass Development in Bhutan
“An Experience in cool temperate environment”
The grasses we use today for lawns have been around for centuries evolved in the
meadows and forest glades grazed by large animals. The densely formed grasses that
survived in these ecosystems are those that had low growing points and grazers did not
eat them. A lawn is made up of thousands of individual grass plants or in mixtures of
more than one grass species. Like any other plants, specific conditions must be met for
proper growth to occur to lawn grasses. When each plant is completely healthy, a lawn
has the look of a “rolled-out carpet”.
Photo 1 & 2: Newly established lawn in front of Outlet centre, RDC, Yusipang.
The first experience with the lawn grass development in Bhutan was in the early 80s
when Royal Golf course in Thimphu was developed. Although the lawn grass
development in general is a recent phenomenon, it is gaining popularity amongst the
urban dwellers especially in the growing towns such as Thimphu, Paro, Phuntsholing etc.
2. Benefits
Lawns serve different purposes. A lawn is pleasant scenery for a home landscape that ties
together the surrounding flower gardens, ornamental trees, and shrubs. Also a lawn is
used as an outdoor living room during warm weather. Other advantages of lawn are that
turf grasses controls dust and reduce pollen in the air from plants that can cause allergy
problems to some individuals. Turf grasses absorb gaseous pollutants such as carbon
dioxide converting them to oxygen (Imperial lawns, USA). Lawns also benefit home
landscapes in many environmental ways as well. When it is hot, a lawn reduces glare
from the sun and keeps the surrounding area cooler. When it is windy, the blades of grass
trap particles of dust and when it is rainy; a lawn stabilizes soil and prevents erosion
problems.
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3. New Lawn Establishment
Photo 3: Perfect place for fun
It is necessary to know the important steps of the lawn development techniques. The
successful lawn establishment means doing the “right thing at the right time”.
4. Planning
Much success depends on how well you plan your lawn development. There should be
provision for basic equipments and inputs (Table 1). A turf grass is available in two broad
categories, warm season grasses and cool season grasses. Cool season grasses are
recommended for warm temperate to sub alpine zones

5. Soil preparation
Preparing a field for lawn development is one of the most vital steps and a good seedbed
preparation is a prerequisite for successful lawn establishment. If the soil is poor, arrange
additional forest topsoil. The topsoil from broadleaved forest is preferred. Topsoil from
the blue pine dominated forest can be used but it has acidity problem. On removing
debris such as stones, wood and other items from the planting area, add the top soil and
the thickness of topsoil should be uniform both on slope and flat areas.
It is advisable to test your soil before adding any nutrient to the soil. A soil test eliminates
guessing the amount of nutrients to be added. Lawn grass species perform well at soil pH
range of 5.5 to 7. For the proper grass growth, if your soil pH is below 5.5 add lime to the
soil and if it is above 7, add sulfur. Organic matter and other soil additives such as
fertilizers can usually be mixed with the topsoil. Lawn requires a larger amount of
inorganic fertilizers mainly Nitrogen, Phosphorus and Potassium (NPK). Lawns require a
large amount of N-Nitrogen to promote growth, color and general vigor. P-Phosphorus
stimulates early root growth to ensure seedlings develop properly. Freshly seeded lawns
require a fertilizer with high phosphorus content. Also P is necessary for proper plant cell
division, which results in a strong, healthy and sturdy grass plant. K-Potassium
strengthens root structure and increases disease resistance, improving the overall
hardiness of grass plants. Even distribution of these materials of soil is most important.
Rake the surface and roll the soil with a heavy roller 90-130 kg to define humps and
hollows. Then rake surface lightly even off these irregularities and to prepare a loose
planting bed of 1/4 -1/2 inch of soil.
Photoes 4, 5, & 6: Different stages of land preparation for lawn establishment
6. Seed rate and sowing time
Seed rate while sowing depends on what lawn species one chooses and size of seeds. For
instance Tall fescue (Festuca arundinacea) is 130kg per acre and whereas Kentucky
bluegrass (Poa pratensis) seed rate is 35-40 kg/acre is applied. Lawn can also be sown in
mixtures of 2-3 grass types. When a mixture containing seed two or more types of is
applied, it has an advantage-the strength of one grass type compensates for the weakness
of another. For this reason, a mixture is best for the average lawn. Broadcast the seed by
hand. In order to ensure uniformity distribution of seeds over a bed, use half the seeds
first and sow remaining half in a crosswise direction. It is important to remember the best
sowing time is when air is calm.
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The best time to sow lawn seeds is in early spring (late March - early May) under
irrigation in the cool temperate environment. Lawn can also be sown in summer but the
heavy rain shower can affects the germination and establishment. The alternative sowing
time is towards the end of rainy season i.e.; mid September to end September when the
optimal temperature for plant growth still adequate and young plants can survive over
winter. Try to avoid seeding lawn during peak monsoon as lawn establishment is badly
affected due to dominance by seasonal weeds that makes difficult to control. It also
makes difficult to prepare land for seeding due to excess soil moisture. In most cases, the
seeds are washed away and mini gullies are formed and eventually end up with heavy
cost of reseedings – seed, fertilizer and labor. Under such situations mulching can be one
of the control measures but it may not be practical if the lawn area is huge.
It is important to treat your newly seeded lawn with special care. While it is getting
established itself, surround the lawn area with stakes and stretched string to prevent
people and animals from entering the area. Temporary fencing using bamboo materials
can also serve the purpose.
7. Rake and roll
Once the seed is sown, lightly rake the seed into soil, no deeper than the recommended
planting depth for the particular variety. A thumb rule is that the depth should be just
double of the seed size. While raking, care must be taken that the teeth just touch the soil
surface. Too much pressure will cover the seeds too deep or move away some of them
and leave bare spots in the new lawn. Make sure the seed is covered carefully until about
10% is still visible. Finally roll the area with a light roller (25-35 kg) to compact the soil.
If roller is not available, wooden blocks can also be used and ramming should be done
from one direction.
Photo 7 & 8: Wooden blocks and roller used to roll the area after seeding to firm the soil.
8. Watering
Irrigate the lawn soon after the seeding is completed. Frequent light watering promotes
seed germination and rapid establishment. It is important to keep in mind that the seed
bed is kept not dry or become soaked. Under ideal conditions, lawn seed germinates
within 10 -15 days period. Germination rates vary according to the seed type and weather
conditions. For light sprinkling, hand watering usually gives better regulations than a
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sprinkler. New seedlings require light and frequent watering (2 times per day for the first
2 weeks). As grass begins to grow, decrease the watering frequency but increase the
amount of water used each time.
Early morning is the ideal time to water and morning watering has advantage of less
wind, milder temperatures, and adequate water pressure. Watering in the early hours is
also best time to avoid possible spread of disease and fungus. It is important to note that
cool season grasses require more water as compared to warm season grasses. When the
lawn enters dormant periods in winter, watering at an interval of 2 weeks are essential to
keep the crowns of the grass alive. Afternoon watering has several disadvantages as
evaporation caused by the wind and sun is at maximum, and therefore only lesser amount
of water applied actually reaches the lawn. The best advice, though, for when to water is:
“Water when the lawn needs it”.
Photo 9: Manual watering Photo 10: Watering Poa pratensis lawn using sprinkler
9. Mowing and mower
Theory says; “mow a new lawn for the first time after it has grown a third higher than the
regular mowing height.” For example, a lawn that should be maintained at a height of 2
inches or 2 inches high, it should be mowed when it reaches 2.5 to 3 inches. Do not
remove more than a third of the total height of the grass. However, in field conditions,
this is not practical as the soil remains too soft and new grass is too loosely knit to mow
without damage. The best way is to wait and let lawn continue to grow taller than
recommended height for newly established lawn.
Grasses such as Kentucky bluegrass and Tall fescue cannot be mowed too low (below 1.5
- 2 inches) because they do not have enough leaf surfaces to support the plants. The
recommended mowing height for Kentucky blue grass and perennial ryegrass should be
at the height of 2”- 3”and tall fescue 2.5” - 3.5” from the ground level. Always remember
to keep your mower blade sharp to avoid injury to young plants or damage to the turf
grass. At a 2-inch mowing height the grass needs mowing before it reaches 3 inches that
is well established lawn. Weekly mowing is usually enough to maintain the 2-inch
mowing height during growing season. Do not let lawn grasses become over grown
before mowing and always follow recommended mowing height & frequency of mowing.
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Prior to mowing always make a point to walk over the lawn area and check if there are
stones, wires and other debris that could be hazard to operator and mower machine.
Remember always that “Timely mowing is necessary for quality turf-grass and rule of
thumb is to mow enough that you never remove more than one-third of the leaf area per
mowing”
The type of mower depends on the size of the lawn being planned. For a smaller lawn
area, simple mowers such as push reel mower should work. However for the medium and
larger area of lawn grass, power rotary mower and riding mower with powerful engine is
ideal. An important aspect while buying a lawn mower is simplicity of its operation.
Photoes 11, 12 & 13: Simple push reel mower used for mowing small area lawn
10. Use of grass clippings
Grass clippings are too valuable to waste. Literature review says they contain 4%
nitrogen (N), 0.5% phosphorus (P), 2% potassium (K) and small amounts of other plant
nutrients. The best way to handle grass clippings is to leave them on the lawn as it
eventually decomposes & recycles nutrients back into the soil. This is recommended
under proper mowing conditions and with the proper mowing, clippings will be short
enough and quickly decompose within the lawn area. However if the grass is too long,
the grass clipping can clump and damage lawn. Under such situation, grass clippings can
be used for making compost. It is also important to remember that if lawn is diseased
removing grass clipping from lawn area help reduce the level of disease.
11. Lawn maintenance
11.1. Weeding
As it is not possible to treat or sterilize soil and the local weeds dominate the lawn
grasses during the first establishment year. Manual weeding is therefore recommended
during the first year. Usually by the following year, weed is not a major problem.
However presence of White clover (Trifolium repens) plants in the lawn has to be
checked. This fodder legume is very aggressive and can spread through its stolons and
seeds, and can dominate whole lawn area in a season time if the whole plant is not
uprooted at the seedling stage.
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Photoes 14& 15: Young white clover (Trifolium repens) plant & Lawn grass dominated by T. repens
11.2. Top-dressing
It is important to top dress with light dose of N fertilizer in the form of Urea after every
mowing. The recommended dose of urea is 20-30kg per acre. However, excessive
application of soluble nitrogen to the lawn, without any irrigation facilities will damage
the lawn (burn). Always apply inorganic fertilizer N when lawn is wet that is after
irrigation or rain.
11.3. Lawn Renovation
Lawns need to be renovated periodically to encourage vigorous growth. If your lawn is
basically healthy with some bare spots, some minor renovating can make it look like new.
This can be achieved by reseeding or patching it with a piece of sod that is cut to fit the
affected area.
12. Cool season grass
There are many cool season grass species that can be used as lawn. Kentucky bluegrass
alone has more than 100 varieties available in the world market and similarly other grass
species also have many varieties. However in Bhutan, only a few particular cool season
grass species were tested and the grass species that performs well under cool temperate
environments are presented in Table 2.
Table 2: Cool season grass tested in Bhutan
Common Name Scientific Name Varieties
I. Cool season grasses
Kentucky bluegrass Poa pratensis Broadway, Cocktail, Miracle,
Side kick, Compact
Perennial ryegrass Lolium perenne Jessica, Henrietta & Merci
Tall fescue
Festuca arundinaecea Demeter
Red fescue
Festuca rubra
Creeping bent grass (for Agrostis palustris
golf course)
II. Warm season grasses
Carpet grass
Axonopus affinis
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Photoes 16 & 17: Pure stand lawn of Poa pratensis, varieties Broadway & Compact.
Photo 18: Pure lawn of Festuca arundinacea
Photo 19:Lawn of P.pratensis & L. perenne mixture
12.1. Lawn seed sources
Tall fescue and Red fescue can be obtained from the National Feed & Fodder
Development Program, Department of Livestock, Bumthang on demand. Other grass
species are not available in Bhutan at the moment and has to be imported. Seed
production of some lawn grass species are under observations at RDC Yusipang and
intermediate results of seed production is presented in Table 3:
Table 3: Lawn grass seed production at DRC, Yusipang
Common name Scientific name Variety Seed yield kg/ha
Kentucky bluegrass Poa pratensis 452.5
Perennial ryegrass Lolium perenne Flanker 500.0
-do- -do- Meridian 262.5
-do- -do- Matilda 500.0
-do- -do- Mariner 400.0
Source: Livestock Sector, RDC,Yusipang
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Photoes 20, 21 & 22: Pao pratensis and Lolium perenne & Poa pratensis seed production plot at RDC,
Yusipang
For any technical query or clarifications on the lawn grass development, contact can be
made to either of the following addresses:
1. Rangeland and Farming Systems Section
Watershed Management Division
Department of Forests and Park Services
Thimphu
Tel: 323568/323539
2. Livestock Sector
RNR Research & Development Centre,
Department of Forests and Park Services,
Yusipang.
Tel: 771 91124
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