Weeds-Yellow Toadflax

YELLOW TOADFLAX Back

Yellow toadflax is a perennial that reproduces by seed as well as root. The leaves are narrow and approximately two-inch long. Stems are smooth, generally unbranched, and can grow up to 3 feet tall. This noxious weed prefers open, disturbed sites such as roadsides, waste areas, and rangeland. It can adapt in a variety of site conditions, from moist to dry, and does well in all types of soil. This weed has no trouble displacing desirable grasses not only reduces ecological diversity, it also reduces rangeland value and promotes erosion problems.

Because of its early vigorous growth, extensive underground root, and effective seed dispersal, yellow toadflax is extremely difficult to control.

Control

Mechanical: Small patches of toadflax can be hand-pulled for five or six years to deplete the energy reserves of the root system. Viable seeds in the soil may continue to germinate for 10 to 15 years. Mowing reduces seed production, but has little affect on the root system.
Biological: A small black beetle (Brachypterolus pulicarius) damages the tips of the shoots, preventing many of the flowers from developing. The insect can reduce seed production up to 75%. A fruit-feeding weevil (Gymnaetron antirrhini) feeds in the flowers and reduces seed production up to 80%. These insects may slow the spread of toadflax, but may not reduce the size of the infestation. There is a defoliating moth (Calophasia lunula) also available. Livestock and wildlife do not favor toadflax. Chemical: The toadflaxes are hardy plants with waxy leaves and an extensive root system. Herbicides that have been used with some success include dicamba (pre-bloom), chlorsulfuron (spring or fall), and picloram (pre-bloom or fall). Picloram is a "Restricted Use" herbicide and can only be applied by a licensed applicator. These products are registered for use in rangeland, pastures, and other non-crop areas.

When choosing any kind of control method, assure that your choice is suited for your particular situation. Always read and follow the product label before applying any herbicide.