Sesbania, also known as coffee weed, is an annual herb of the legume family that typically grows to a height of 3–10 feet. Sesbania contains saponin, which is toxic to mammals, including livestock and people. Its seeds are especially toxic and can kill cattle.
Like many other weeds, sesbania thrives in disturbed habitats and has trouble colonizing high-quality natural communities. Natural events such as flooding as well as human activities create soil disturbances that allow this plant to become established.
Recommended Practices in Natural Communities of High Quality
Sesbania is not likely to colonize high-quality natural communities in Missouri as it typically grows in disturbed areas. Isolated occurrences may be found on sand bars along streams or along margins of oxbows or marshes.
Spot treatment may best be accomplished by mechanical removal of the stems prior to the production of fruits. Follow-up will probably be necessary for several additional growing seasons if a seed bank is present or if reinfestation occurs.
Another option would be to treat local occurrences with a foliar application of Rodeo (glyphosate) herbicide prior to fruit production. Follow-up will again be necessary if a seed bank exists at the site or if reinfestation occurs.
Recommended Practices on Lands Other Than High-Quality Natural Areas
Control of sesbania is best accomplished by creating conditions favorable for the germination of beneficial plants early in the growing season. Once established, beneficial plants can outcompete newly germinated sesbania. Therefore, control strategies should be performed early in the growing season.
If early control is not possible, late disk-flood often prevents reestablishment of sesbania and creates conditions favorable for fall migrating shorebirds. This can be followed by an early drawdown during the subsequent growing season.
Chemical methods of control include spraying with 2,4-D at the rate of 3/4 pint per acre, applying it with a boom sprayer. One can also wick the plants with Roundup or Rodeo. A mechanical method, such as mowing, should be accomplished prior to seed set if at all possible. One should mow as high as possible to preserve and promote growth of desirable plants in the understory.
Failed or Ineffective Practices
Avoid these practices:
- Burning appears to stimulate germination.
- Soil disturbance by disking also stimulates germination when done in early to mid-summer.
- A late drawdown during elevated temperatures and dry weather conditions stimulates germination as well.