Sericea Lespedeza

Sericea Lespedeza, Lespedeza cuneata (Dumont) G. Don, is a very aggressive, drought-hardy perennial. It was introduced as a forage crop in the Southeastern United States. As early as the 1930s, Sericea was also used for erosion control and wildlife habitats in Kansas. It is now found primarily in native rangeland, CRP, and roadsides in the eastern 1/3 of Kansas. Plants have a dark green foliage that contrasts the native grass color in the early fall. Lespedeza has small, white, purple tinged flowers that bloom in late summer and produce large amounts of seed. It also has a semi-woody stem and can reach five feet in height.
Sericea is a problem because of its ability to compete with native bunch type grasses. It's aggressive behavior allows it to choke out existing vegetation. Sericea also contains a tannin that makes it unpalatable to livestock for most of the grazing season. It can also tolerate and survive most common weed control practices used by farmers and ranchers.

Sericea Lespedeza is spread and proliferates mainly by using rangeland for double stocking cattle or winter pasture, late native hay harvesting wildlife habitat. Some CRP areas were planted with sericea-contaminated seed.

During the 1998 Kansas Legislative session, lawmakers amended the Kansas Noxious Weed Law to include Sericea Lespedeza as a noxious weed. The statute was written to allow time for further research and sericea did not officially become a "noxious weed" until July 1, 2000. Counties had the option to make it a noxious weed within their borders early, by resolution and publication. This allowed for enforcement and cost-share chemical availability, but did not address the movement of sericea seed in grass forage seed.

Sericea Lespedeza is often confused with its palatable cousin, Korean Lespedeza. Other similar species are Heath Aster, Japanese Lespedeza, Slough Grass, and White Snakefoot.

Vegetative Characteristics

Sericea lespedeza is a perennial with erect stems up to 5 ft. tall and small hairs laying flat along the ridges on the stem. The leaves, with 3 leaflets, are less than 1 inch to 1 1/2 inches long and 1/4 to 1/2 inch wide with the larger leaflets on the lower portion of the stem. The leaves are flattened on the outer end with small flat hairs on the lower surface. Flowering occurs from mid or late July to October and may be tinged with purple but always dry to yellow. The tannin content of sericea lespedeza increases during the growing season, making it unpalatable to livestock during mid to late season grazing.

Reproductive Characteristics

Sericea lespedeza reproduces primarily by seed. Seeds move with water, infested hay, birds, livestock and wildlife. The hard seed passes through the digestive tract of animals.

Specific Controls

Sericea lespedeza can be treated with a variety of cultural, mechanical, and chemical means. Preventing seed production and its spread is of primary importance for control. The Jefferson County Weed Department is promoting a holistic farm management approach as the most effective control for sericea. This method involves using many different strategies to eradicate the problem. The Jefferson County Weed Department encourages farmers to develop a management plan to coordinate and facilitate these holistic practices. Examples would include the use of pasture burning, mowing, fertilization, selective grazing, and tillage in conjunction with approved herbicide use.

Management Options

Inspect all pastures and rangeland in July, August and September. Early detection of the presence of Sericea Lespedeza is essential to economical control.

Mechanical/Cultural Control

  • Sericea cannot withstand normal tillage practices
  • Repeated mowing will reduce seed reproduction and plant vigor
  • Burning can be a valuable tool in controlling Sericea Lespedeza
  • Avoid double stocking or fall pasturing livestock in infested areas
  • Fertilization in cool season grasses will discourage Sericea from spreading
  • mechanical and cultural practices should be used in conjunction with other control methods

Herbicide Recommendations

PastureGard - 1 gallon containers
  • Pastures and CRP
  • Cool and warm season hay fields
  • Feedlots and waste areas
  • Spot application
  • Only apply under good soil moisture conditions
  • Controls Sericea Lespedeza and other broadleaves, but does not kill grass
MSM - 8 ounce containers
  • Pastures and CRP
  • Cool and warm season hay fields
  • In areas where Musk Thistle is also a concern
  • Only apply under good soil moisture conditions
  • Must be applied by a commercial applicator
  • Controls Sericea Lespedeza and other broadleaves, but does not kill grass

Factors for Best Control

Helpful Information in controlling Sericea Lespedeza

  • Only apply herbicides when adequate soil moisture conditions exist
  • Use large amounts of carrier water when applying 5 gallons or more Aerial, 15 gallons or more ground
  • Commercial application will save money in the long run
  • Spraying Sericea Lespedeza with 2,4-D is a waste of time and money
  • Avoid double stocking or fall pasturing infested areas and dry lot cattle coming from sericea infested areas
  • Burning activates sericea seed germination
  • Fertilization in cool season grasses will discourage infestation from spreading
  • Mowing will reduce sericea production. Haying is permitted if done before seed production
  • Do not allow infestation to spread to timber areas

Prevention of Spread

Do not move hay that may contain viable seed from infested areas. Feed noxious-weed-free hay and forage. Check the labels of grass seed and grass seed mixtures for the presence of Sericea Lespedeza prior to purchase. Do not move mature cattle in late summer through October from an infested pasture to a clean pasture.