Identification

Only dodder seedlings have roots, its tangled stems are usually orange, but may be yellowish, whitish, or greenish or even tinged with red or purple. The plant's tiny leaves are scale-like and almost invisible, whereas the numerous clusters of little waxy cream colored 5-petaled flowers and subsequent 1/8" seedpods are more noticeable. There are 2 to 4 3-sided brownish seeds in each 2-celled capsule.

The USDA classifies dozens of dodder species as Noxious Weeds. American dodder (C. americana) and golden dodder (C. campestrisis) are particularly damaging agricultural weeds. Dodder is a major problem for such crops as alfalfa, clover, and flax. Other plants commonly parasitized by dodder include many daisy relatives (especially chrysanthemums), Virginia creepers, trumpetvines, English ivies, petunias, camellias, citrus, beets, redbuds, hollies, sumacs, buttonbushes, cucumbers, raspberries, potatoes, tomatoes, roses, coleus, impatiens, and various legumes. Dodder can also carry plant viruses, including Phytoplasma, which is responsible for many of the "yellows" diseases.

Culture

Dodder is usually regarded as an annual, but tends to be a perennial in Florida. Some species are salt tolerant and/or herbicide resistant.

Light: Dodders grow most vigorously in full sun.

Moisture: Moisture requirements vary according to host plant. Some species grow in marshes, others in arid scrub-lands.

Hardiness: USDA Zones 4 - 11.

Propagation: Dodder reproduces readily from seed. A single plant may produce thousands of seeds, which can remain viable in the soil for many years.

Control

Since it will grow on so many different plants and its dormant seeds stay viable a long time dodder is hard to control and nearly impossible to eradicate. Dodder seed can be spread by irrigation water, in the manures of livestock that have eaten infested alfalfa, or along with the seed of crops that were infested with dodder. Pre-emergent herbicides such as DCPA (Dacthal), applied to the soil in the spring before seed germination will prevent this pest. Follow label directions!

Pulling and destroying dodder infected plants is recommended. Dodder must be destroyed before it produces seeds otherwise infestations will spread. Once established, dodder appears in patches in the field. Cutting infected host plants prior to the dodder producing seed helps to reduce the quantity of seed for the following year. Planting an infested field with an immune or resistant crop such as cereals, corn, soybeans, velvetbeans or cowpeas helps to control this weed.

The use of a 2,4-D type herbicide or contact herbicide sprayed on infected hosts and dodder plants will effectively kill established parasitic plants (and the host plant).