Sericea lespedeza has good points as well as bad ones

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By Ted Manzer

Friday, August 24, 2018

Most of our land is not prime farmland. Some places have problems with soil moisture, fertility or erodibility. We can’t grow row crops anywhere we want, and we usually can’t afford to fertilize places that may not provide a return on our investment.

Enter sericea lespedeza. It was brought to this country as early as the 1890s. Throughout much of the 20th century is was used as a forage on marginal land. It was also used for erosion control. Most of you have likely seen it but never paid it any mind.

From a distance, sericea lespedeza looks a little like rosemary. It’s a semi-woody plant that often grows five feet tall. Upon closer inspection there is little resemblance except for growth habit. There is little branching. Leaves emerge from stems singly and are composed of three slender blades.

Sericea lespedeza is in the pea and bean family just like clovers and alfalfa. Plants in that family can form a symbiotic relationship with nitrogen fixing bacteria. This means they often don’t need to be fertilized with nitrogen, the element most responsible for plants’ dark green color.

This tough legume tolerates a wide range of soil conditions. It also forms a deep root system that helps prevent erosion. For that reason, it was a popular choice on roadsides, reclaimed strip mines and rangeland.

Its merit as animal feed is mixed. Cattle don’t particularly care for it, so beef production is low. Goats, on the other hand seem to love it. There also seems to be another benefit for sheep and goats when fed a significant amount of this legume in their diets.

Sericea lespedeza appears to be a natural deworming material. Results are mixed, but many goat farmers swear by lespedeza hay and pasture. Part of the reason for this benefit might be the high amounts of bitter tannins in the leaves. That’s also the most logical reason for its low palatability with cattle.

Goats thrive in lespedeza pastures and will readily eat lespedeza hay. When fields are stocked with goats there is no need to try to eliminate lespedeza from the area. Otherwise, this plant has many downsides.

Pastures often develop a large percentage of lespedeza because it shades out shorter growing plants. Beef farmers can naturally thin out lespedeza by letting goats graze with the cattle. Over time the stocking rates of each can be adjusted and the forage composition is also changed.

For those simply wishing to eliminate this plant, many herbicides will control it. Round-up is a popular non-selective herbicide but a high rate must be used. Furthermore, Round-up kills the grasses too. PastureGard and Grazon are popular selective weed killers that kill only broadleaf plants.

A reason for removing this plant from the landscapes is that it reduces biodiversity and creates monocultures. That topic has gained traction in recent years. In the western prairies, Sericea lespedeza limited natural food supplies for many native rangeland birds. The same is probably happening but to a lesser extent here in the east.

Ted Manzer teaches agriculture at Northeastern High School.