Common Lespedeza

What is common lespedeza?

Common lespedeza is a warm-season annual legume from East Asia that moves into lawns wherever grass is thin and short on fertilizer. common lespedeza identification starts with the leaves: three small, smooth-edged, oblong leaflets on wiry stems lying flat on the soil, followed in summer by tiny pink to purple pea flowers tucked along the stems.

It crowds out weak turf and stays so low the mower rides over it. Like clover, it fixes nitrogen from the air through root nodules, so it thrives where grass is hungry, and its shallow taproot handles dry, compacted ground. Once summer heat toughens its stems it gets much harder to kill, and turf specialists often read a big patch as a sign the lawn needs more nitrogen.

Common Lespedeza identification: what to look for

From standing height it passes for clover, so kneel down and study one stem. The leaflets are longer than wide, the side veins are fine and parallel, every leaf has brown stipules at its base, and the flowers sit tight in the leaf axils instead of on stalked heads.

• Leaves: Three oblong leaflets per leaf, 1/4 to 1 inch long, smooth-edged, darker green above and paler below, with straight parallel side veins.
• Stems: Wiry, round, green to purplish, with small white hairs pressed flat and pointing downward. They turn reddish brown and woody by midsummer.
• Stipules: A pair of small brownish stipules at the base of each leaf stalk.
• Flowers: Pea-shaped, about 1/4 inch long: a pink or purple lower petal with two small white upper petals, one to three per leaf axil.
• Seed pods: Flat oval pods about 0.2 inch long with a single seed each.

Where it grows in the United States

Common lespedeza is mainly a weed of the Southeast, lower Midwest and southern Plains. NC State Extension records it as introduced from Florida and Texas north through Oklahoma, Kansas, Kentucky and Illinois, and up the East Coast to Maryland and New York. Mississippi State Extension calls it a troublesome turf weed across most of the southeastern US.

It favors full sun, sandy soil (though it tolerates clay), acidic to neutral pH, drought, compaction and low fertility, and it invades every turfgrass type where soil is poor or nitrogen is short. Roadsides, golf roughs and pastures carry big populations that mowers and equipment track into lawns.

Common Lespedeza look-alikes

A few plants get mixed up with it:

• Korean lespedeza (Korean clover) (Kummerowia stipulacea): Taller and coarser, with broader leaflets. Its stem hairs point up the stem; common lespedeza's point down.
• Black medic (Medicago lupulina): Its leaflets are finely toothed, the middle one sits on a short stalk, and it bears small clusters of bright yellow flowers that become black pods. Lespedeza is smooth-edged with pink-purple flowers.
• White clover (Trifolium repens): A perennial whose creeping stems root at the nodes, with white to pale pink flowers in round heads. Lespedeza grows from one taproot and its flowers sit in the leaf axils.

How to get rid of common lespedeza

Pulling, digging and mowing: Hand-pull young plants and small, new patches, ideally when the soil is moist. Each mat grows from one shallow taproot, so grip near the center and lift. Get plants out before pods ripen in late summer. Mowing helps little, since the plant tolerates very low mowing, and survivors turn tough and woody by late summer.

Cultural control matters most, because the right conditions keep it from coming back.

• Fertilize on schedule using your local Extension nitrogen recommendations; underfed grass loses to a plant that makes its own nitrogen.
• Mow at the top of your grass's recommended range; about 3 to 4 inches for cool-season lawns.
• Test the soil and correct pH as recommended.
• Core aerate compacted areas, limit traffic, and water deeply but less often during drought.
• Wash the mower after cutting infested areas.

Herbicides: Treat young, actively growing plants; in the South, start scouting in March or April, and expect follow-up applications. Preemergence products containing dithiopyr, pendimethalin, prodiamine, atrazine or simazine reduce seedlings, and mid- to late-spring timing has beaten late winter. After emergence, metsulfuron-methyl gives good to excellent control in many warm-season lawns, and combinations of 2,4-D, MCPP (mecoprop) and dicamba work when applied early and repeated; 2,4-D alone does poorly. Not every product is labeled for every grass (atrazine and metsulfuron, for example, are not labeled for tall fescue), so choose one labeled for lawns and your turf species, keep dicamba away from tree and shrub roots, and follow the label exactly. The label is the law. If you hire someone to spray, make sure they hold your state’s pesticide applicator license; the rules for each state are in our pesticide applicator license guide.

Keeping it from coming back

A dense, well-fed lawn is the best defense. Lespedeza seed sprouts every spring wherever sunny soil is open, so fill thin spots, keep fertility and pH where your grass needs them, and fix compaction before it opens the door.

Break the seed cycle by removing plants before pods ripen, and clean equipment after working roadsides, fields or infested areas.

Questions we get about common lespedeza

Similar weeds

Black MedicMedicago lupulinaWhite CloverTrifolium repensBurcloverMedicago polymorpha