Proposed Dates of Use: (POSTPONED) October 4 – November 22, 2024; as weather conditions and operational factors permit.
Street Address/Site Name: Various Open Space Managed Areas: South Fork Preserve, Howat Ranch, Wildhorse Ag Buffer
Detailed Location of Application Site: Throughout Open Space managed 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: RoundUp, Vastlan & MSO Surfactant
Product (W/ active ingredients): RoundUp Custom (Glyphosate, N-(phosphonomethyl)glycine, in the form of its isopropylamine salt 53.8%)
EPA Reg #: 524-343
Pesticide Type: Herbicide
City Use Type: Tier I. Most Hazardous. Most Restrictive.
Product (W/ active ingredients): Vastlan (Triclopyr choline: 2-[(3,5,6-trichloro-2-pyridinyl)oxyacetic acid, choline salt)
EPA Reg #: 62719-519
Pesticide Type: Herbicide
City Use Type: Tier II. Less Hazardous. Less Restrictive.
Product (W/ active ingredients): MSO Surfactant - Methylated vegetable oil, alcohol ethoxylate, phosphatidylcholine 100%
EPA Reg #: CAS No. 97281-47-5, CAS No. 67784-80-9, CAS No. 34398-01-1
Pesticide Type: Adjuvant
City Use Type: Tier II. Less Hazardous. Less Restrictive.
Target Pests: Pepper weed, Invasive ryegrass, Arundo, Tamarisk, Himalayan Blackberry, Annual grasses, Bermuda Grass
Justification for Use: This herbicide use is justified due to Staff’s need to mitigate and suppress noxious and invasive species in Open Space areas. These species cannot solely be managed by hand or mechanically due to their growth characteristics. Mowing or string trimming are not effective methods to control the vegetation within these specific areas because they may cause damage to desirable natives and disperse seed heads, while other targeted species have large roots and reproduce vegetatively, meaning that digging or cultivating can actually spread the issue.
Explanation of IPM Methods Used: Other acreage included within the Open Space management areas are maintained using a variety of IPM techniques, including strategic and well-timed chemical use. Staff currently employ almost exclusively non-chemical control measures at the majority of our Open Space sites including mowing, trimming, hoeing, hand pulling and solarization. Staff found out last year’s solarization was not an effective method to control vegetation on the paths due to the gravel's interference with the process of heating the soil.
Strategies to Prevent Future Applications: Well-timed chemical spot applications will kill and suppress the targeted noxious and invasive weeds and reduce the need for future chemical applications. Once large, unwanted sections of vegetation are suppressed, Staff can mitigate the establishment of new invasive vegetation through mechanical and physical methods.
More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management
