P&PDL Logo

Picture of the Week for 16 August 1999

Dodder, Cuscuta sp. -- Attack of the String Monster!

B. Rosie Lerner, Consumer Horticulture Extension Specialist

(Photo courtesy of Phil Sutton, AgNR Educator, St. Joseph county.)

The following information is from Down the Garden Path, Issue #84, August 14, 1995.

DodderIf you've run across a stringy yellow mass attacking your garden, don't panic. No, it isn't a visitor from another planet, but it may be a plant that sounds like it belongs in a low-budget science fiction movie!

Dodder is a parasitic weed that must obtain its moisture and nourishment by attaching to a green, living plant. It belongs to the Morninglory family, but it bears little resemblence to the garden types, other than its vigor.

Dodder is an annual that reproduces by seed. As the seedlings emerge, they begin twining around any type of support that might be available, especially garden plants. The yellowish-orange, string-like stems form dense masses while sending root-like projections into the host plant (your treasured flower, vegetable, or shrub!)

The plant appears to be leafless but may in fact bear tiny bracts. The clusters of tiny white flowers eventually give rise to small pods containing seed, providing opportunity for dodder to invade your garden in future years!

Now for the really bad news. There is no herbicide that can be applied to garden or landscape plants once dodder is growing on those plants. Hand-pulling and pruning is the only method of control once the dodder is established. Prior to germination, dodder can be prevented reasonably well with the application of a pre-emergence herbicide called Dacthal. Be sure to read and follow all label directions before using any pesticide.


Top of page. | Current Picture of the Week | Past P&PDL Pictures of the Week

|P&PDL Home Page |

Last updated: 1 July 2002/tlm.
The Plant & Pest Diagnostic Laboratory at Purdue University.