COSCA Invasive Species Management 2026

Summary

COSCA is seeking proposals for the removal of invasive plants on five (5) work sites with six (6) target species consisting of fennel ( Foeniculum vulgare ), yellow star thistle ( Centaurea solstitialis ), artichoke thistle ( Cynara cardunculus ), Russian knapweed ( Acroptilon repens ), tree spurge ( Euphorbia dendroides ), and carnation spurge ( Euphorbia terracina ) . Project sites are distributed throughout COSCA's open space system (Figure 1) and described in detail in the project scope of work. The extent of the treatment area at each location is illustrated in Figures 2 – 6. Treatment is to occur in the order that tasks are listed in the scope of work. The selected entity for the project shall demonstrate prior experience with non-native plant management projects, shall be highly proficient in native and non-native plant identification, and shall possess a valid C-27 Landscape Contractor License from the state of California. Treatment methodology will entail spot application of herbicide. The contractor shall be licensed by the California Dept. of Pesticide Regulation (CDPR) as a Pest Control Operator, and the individual(s) performing the application shall possess a Qualified Applicator’s License or Certificate (QAL/C) from CDPR, or be under the direct supervision of a QAL/C. Tank mixes shall include a non-ionic surfactant (e.g. Agridex) and a photodegradable marking dye to facilitate visual confirmation of the extent of the application area by the applicator.