Proposed Dates of Use: As conditions and time permit during working hours on December 6 & 7, 2022.

Street Address/Site Name: Wildhorse Agricultural Buffer

Detailed Location of Application Site: Throughout buffer area and along path from Pole Line Rd to Covell Blvd – sections of path with be temporarily closed during the application.

Posting and Notification: Site notifications will be posted at least 24 hours before application via the pesticide application electronic notification system and at site entrances, remaining 24 hours after.

Pesticide Products: Capstone (Triclopyr Triethylamine Salt, Aminopyralid Triisopropanolamine Salt)
EPA Reg #: 62719-572
Pesticide Type: Herbicide
City Use Type: Tier II Limited-Use, more restrictive 

Target Pests: Yellow Star Thistle, Italian thistle, short-pod mustard, black mustard, milk thistle, fluvellein, stinkwort, other broad-leaf weeds on the site.

Justification for Use: This herbicide use is justified due to the size of the site, size of infestation and growth stage of the existing weeds. The current infestation is largely a result of continued pressure from surrounding land uses including agriculture and county roads. The weeds reduce the amount of grass cover and therefore change the composition and structure of the habitat, reducing its value. Other weeds, including yellow star thistle, provide significant fuel for fire, burning hotter than grasses due to a high oil content. There is no reliable way to kill these weeds using non-chemical methods at the scale they exist on the sites. 

Other than the reasons mentioned above, mechanical cultivation is not an option because the soil disturbance will hurt or kill the native grasses. Exposing soil could also allow for more weeds over time. Open Space does not have access to the amount of labor necessary to go through the treatment area and hoe or hand-pull each plant to kill it and prevent seed set, plus the amount of soil disturbance would be similar to mechanical cultivation.

More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management