Dodder is also known as strangle weed, pull-down, hellbind, devil’s hair, love vine and hailweed. It is a parasitic plant, Cuscuta sp. that grows from a seed. The seeds germinate in the spring and send up long, twining thread-like stems. The vine attaches to susceptible plants and twines around the stems and petioles. By the time dodder becomes noticeable, the thread-like stems are yellow to orange in color. There are no leaves on the slender, twiney stems.
Host plants are weakened, stunted, and may fall over. Field infestations start as circular areas and continue to enlarge during the growing season. Yields of legume crops, such as alfalfa, lepedeza or yuchi clover, can be greatly reduced. The greatest loss occurs in legumes grown for seed. Seed cleaning may also be a major cost. Only certain levels of dodder seed are tolerated in crop seed sold in Texas. Southern greens infected with dodder are not acceptable to processors. Onion yields can be reduced. Thickets of live oak sprouts and other woody plants are attacked by some dodder species. Small grains, corn sorghum, and other grass crops are not hosts of dodder.
Control is best achieved by preventing introduction of dodder into fields either with planting seed or by infected plant material. Equipment should be cleaned before moving it from dodder-infested fields. When an infestation is present, spot treat with a herbicide that will kill the host or use a weed burner. Certain herbicides (Dacthal, for example) that prevent germination or kill in the seedling stage can be used when entire fields are infested. Homeowners with contaminated flower beds should handpick the dodder and destroy it before seeds are formed.
See USDA Farmers’ Bulletin No. 2276.