Vegetation Management and Maintenance Plan - Watsonville ...

Table 4. Levels of Invasive Weed Infestations and Potential Control Techniques, Watsonville Wetlands Trail System Project Area
Common
Name
Scientific Name Invasive Weed
Ranking
Infestation
Threshold
Growth Pattern
Potential Control Techniques
Harding grass
Reed canary
grass
Bristly oxtongue
Wild Radish
Phalaris aquatica
P. arundinacea
High
Patch greater
than 100 sq. ft.
Perennial
Spreads by seed and
spreading underground
stems (rhizomes). Limited
rhizome spread by
Harding grass. Extensive
rhizome spread by reed
canary grass
a. Avoid mechanical cutting of rhizomes and transport of
cut pieces to new locations.
b. Remove small patches, removing all root pieces and
seed heads, bag and dispose.
c. Mow close late in season to reduce vigor, repeat
several years. Apply herbicide.
d. Graze with geese low during the growing season to
control. Apply herbicide.
e. Solarization for >1 year with 10mm black plastic.
f. A critical component to control Harding grass is:
Revegetate treated areas with native perennial grasses;
spot remove young Harding/canary grass seedlings.
Management Goal: Reduce size of existing patches to