Yellow Toadflax

Yellow toadflax, (Linaria vulgaris) was first introduced to North America in the mid 1800s by a Welsh Quaker named Ranstead. The toadflax flourished in his Delaware flower garden. It was soon cultivated in other gardens. Many decades later, yellow toadflax also know as common toadflax or butter and eggs is designated as noxious in B.C. Under the Weed Control Act this means that all land occupiers have the duty control plants that have been designated as noxious. Yellow toadflax has a creeping root system that grows from 1 to 2 metres per year. This is mainly how it spreads. The root buds start 2 to 3 weeks after the seed germinates. It also spreads by seed but most of the dark brown seeds usually fall within a metre of the plant. The seeds have black or brown papery circular wings, so they can travel far on the wind but usually don’t. Each plant has the potential to produce up to 30,000 seeds. The seeds have a low germination rate but can remain viable in the soil for up to 8 years. Yellow toadflax is a perennial that grows up to 0.8 metres tall. The stems and leaves are smooth. It has narrow leaves that are up to 10 cm long and up to 1 mm wide. It has bright yellow snapdragon like flowers with an orange spot on the lower lip. The flowers are similar dalmatian toadflax but smaller. Yellow toadflax is found in a variety of habitats. It can be aggressive and persistent. Because of its creeping root system, it creates dense patches that suppress other plants. Yellow toadflax contains a glucoside that is reported to be unpalatable and moderately poisonous to livestock. While it can be difficult to control there are several control options. Herbicide is effective in the control of toadflax. There are biocontrol agents for yellow toadflax. There are manual control options as well. Mowing can help to starve the roots, but mowing should be done before seed production. Pulling can work but it will take multiple treatments and works best in soft soils. It only takes a piece of lateral root as small as 1 cm to grow a new plant. Seeding after treatment of any kind will help create competition. Grazing is not a viable control measure. A combination of control and prevention measures are the best choice for success. For more information on invasive species please contact the Boundary Invasive Species Society at 250-446-2232, www.boundaryinvasives.com, info@boundaryinvasives.com and on Facebook.