Invasive plant species pose a threat to the delicate biodiversity and natural beauty of The Preserve. Left unchecked, these species have the potential to out-compete sensitive native species and disrupt our treasured native plant communities. Some top priority invasive species include: French Broom, Yellow Starthistle, Stinkwort, and Pampas Grass. These plants may require intervention and control measures to reduce their spread, mitigate their impact, and stave off the threat to our native ecosystem. Weed species require consistent monitoring and treatment to ensure their eradication, and can be controlled by hand removal, mowing, or herbicide application. Standards for managing invasive weeds in the Homelands are outlined in our 2019 Weed Management Guidelines. For Openlands management, the Conservancy works with individual homeowners to devise a targeted weed management plan to eradicate invasives on The Preserve. The Conservancy also offers a series of diverse events open to members that educate and provide hands on exposure to conservation issues and practices. An events calendar can be found here.
The Conservancy’s top invasive weeds for erradication include: French Broom (Genista monspessulana), Poison Hemlock (Conium maculata), Invasive Thistles including Milk thistle, Yellow Starthistle, and Bull thistle (Carduus spp., Silybum sp., Circium spp.), and Stinkwort (Dittrichia graveolens). Timing of treatment and annual maintenance are imperative for removal of invasive weeds. Control and eradication of these persistent plants can take several years to deplete the seed bank in the topsoil. The goal of treatment: remove weeds before they can set seed.