Proposed Dates of Use: September 4, 2026; as weather conditions and operational factors permit.
Street Address/Site Name: County Road 105(Howat Ranch) Detailed Location of Application Site: Throughout managed areas, including: trails, developed parking areas, kiosks and seating areas, roads, fence lines, access points, habitat areas.
Posting and Notification: Site notifications will be posted at least 48 hours before application at site entrances and will remain posted for 24 hours, and via the pesticide application electronic notification system.
Pesticide Products: Vastlan, Activator 90
Product (W/ active ingredient): Vastlan (Triclopyr choline 54.72%) EPA Reg #: 62719-687 Pesticide Type: Herbicide City Use Type: Tier II. Less Hazardous. Less Restrictive.
Product (W/ active ingredients): Activator 90 (Alkylphenol ethoxylate, Alcohol ethoxylate, Tall oil fatty acid 90%) CA Reg #: 34704-50034 Pesticide Type: Adjuvant City Use Type: Tier II. Less Hazardous. Less Restrictive.
Target Pests: Small Woody Vegetation, Various Perennial & Annual Weeds including Stinkwort, & Pepperweed
Justification for Use: The use of herbicides are justified as the products will aid in suppressing the weeds that are not able to be managed solely by hand or mechanically due to their vegetative growth characteristics or proximity to desirable plants. Mowing and string trimming are not feasible ways to manage the unwanted vegetation as the equipment unintentionally scatters vegetative material and promote new growth throughout the site. Other species have large roots which disrupts the landscape for desirable plants when dugout or from other cultivating methods.
Explanation of IPM Methods Used: Staff primarily employ non-chemical control measures throughout Open Space sites: including but not limited to mowing, trimming, hoeing, hand pulling and solarization. Past experience with solarization was shown ineffective to control vegetation on large uneven terrain. Additionally, well-timed chemical applications have shown to be an effective tool. Past applications of Lifeline has shown well to control mixed weeds in trails and paths; Vastlan has shown well for Himalayan Blackberry and Pepperweed. While Transline and Capstone continue to effective control thistle. Grazing and prescribed fire has been re-incorporated as a vegetation management tool to great success.
Strategies to Reduce Future Applications: The Division’s primary strategy to reduce future herbicide applications includes continuing to use other non-chemical techniques to prevent re-emergence; following up with well-timed chemical applications as needed. Seeding with natives, using mulch, altering irrigation regimes and scouting for infestation sources are additional ways to prevent future chemical use. Some problematic sites may require multiple applications to effectively manage and/or suppress the undesired vegetation. Tank mixing Vastlan with Telar to prevent resistance at problematic sites will continue.
More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management
