Common Toadflax
Common (or yellow) toadflax is a noxious weed which is native to Europe and was introduced to North America as an ornamental. It prefers well-drained sandy or gravelly soils, dry summers, and open, sparsely vegetated sites. These weeds contain a poisonous glycoside that may be harmful to livestock if consumed. It readily colonizes grasslands, open forests, roadsides, railroad tracks, logged forests, cultivated fields and gravel pits. In Alberta, almost 70,000 acres are infested with toadflax.
Yellow Toadflax is a creeping perennial which begins growth in the early spring. It reproduces by seed as well as through its creeping roots. Taproots may be up to one meter long, while lateral roots may be several meters long and can develop buds capable of forming new plants. Plants flower from May to August, and seeds mature from June to October. Seeds can remain dormant and viable in the soil for up to 10 years, and a single toadflax plant can produce up to 30,000 seeds annually.
Control Options:
- Best control option is to stop the plant from going to seed.
- Pulling or cultivating young plants in small infestations before they go to seed will provide control if done consistently for several years.
- When pulling the weed, make sure to remove the lateral roots completely as the root can tear and underground portions can survive, causing new plants to sprout.
- The site will need to be attended to frequently (several times per season) to completely eradicate the weed.
- Mechanical control (tillage) is not recommended for control of medium or large stands of this weed.
- While mowing can be used to control the weed prior to herbicide application, it is not otherwise recommended as it stimulates more plants to grow from the roots. While mowing before the plant seeds reduces the number of seeds available for germination, the stand density may increase from root sprouting.
- Providing competition with desirable plants is a good option following other control methods which have already controlled the weed.
- Check your Crop Protection Guide for herbicide advice.
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