Thistle management

While a warm, wet spring has meant abundant growth of flowers in gardens and wildflowers in the high country, it has also led to an explosive growth of noxious weeds. In particular, invasive thistles – Scotch, musk, plumeless, bull and Canada – have proliferated in Garfield County. Many of the biennial thistles – Scotch, musk, plumeless, and bull – have already flowered and are well on the way to seeding out or have already done so. Once the biennials start to seed out, they have completed their life cycle and spraying at this point is ineffective. For flowering biennial thistles,