Sericea Lespedeza: Noxious Weed, Goat Dewormer, or Both?

By the XES Netting team — bale net-wrap manufacturer · Updated August 10, 2026 · ~15 min read

Few forage plants split a room like sericea lespedeza. In one county it arrives as an enforcement letter telling you to spray. Two states away it is a bagged, named cultivar with a seed tag and a price. In the small-ruminant world it is a research subject with a decade of peer-reviewed parasitology behind it.

All three of those are the same species. This guide is for hay producers and graziers who need to work out which situation they are actually in — how to identify the plant, what your legal obligations may be, what controls actually work, and what the research does and does not support about feeding it.

First: make sure you have the right lespedeza

This is where most of the confusion starts, and it is genuinely important because the answer changes from "spray it" to "that's good feed."

Several lespedezas grow across the Midwest and Southeast. K-State's identification bulletin puts the key distinction plainly: all of the Midwest lespedezas are perennial except Korean and common lespedeza. Those two are introduced annuals, commonly used in tamegrass pastures, and are considered valuable forage in southeast Kansas, southern Missouri and northeast Oklahoma.

Graziers who run both know the difference well:

Annual/ Korean/ Common/ Kobe lespedeza has been called "Poor-Man's alfalfa" by the old-time farmers.. highly nutritional and grows well where alfalfa struggles.

AND is not even close to being hated like Sericea Lespedeza !!

— Holistic Grazer · HayTalk thread 11770

There are also native perennial lespedezas — roundhead, violet and slender. K-State notes none of these has shown sericea's invasive nature, and that slender lespedeza is the easiest to confuse with sericea: same tall, coarse, branched stems, but different flower colour and leaf shape. Slender lespedeza flowers range purple to pink, and its leaves are linear or elliptical with a rounded tip and base — no conspicuous point.

How to identify sericea lespedeza

From the K-State description, working top to bottom:

• Habit: shrubby, deciduous perennial, roughly 2 to 5 feet tall, with coarse single or clustered stems and numerous branches, densely leaved.
• Leaves: trifoliate on short petioles. Leaflets are club- or wedge-shaped — wider at the tip than the base — about 1/4 to 1 inch long and 1/16 to 1/4 inch wide, round to flat at the top with a conspicuous point at the tip. The lower leaf surface has silky hairs.
• Flowers: yellowish-white with purple to pink markings, about 1/4 inch long, in clusters of 1 to 3 in the upper leaf axils, appearing mid-July to early October.
• Seeds: small, 1/16 to 1/8 inch, tan or greenish.
• Regrowth: new growth each year comes from buds on the stem bases or crown, about 1 to 3 inches below ground — which is why mowing does not kill it.
• Roots: a deep woody taproot with lateral branches down to 3 to 4 feet.

The two features that separate it fastest in the field are the wedge-shaped leaflet with a point at the wide end and the cream/yellowish-white flower with a purple throat. If the flowers are clearly purple-pink and the leaflets are rounded at both ends, look at slender lespedeza instead.

The legal side: how a planted forage became a noxious weed

The history explains the paradox. Sericea lespedeza was first planted in the United States in 1896 at the North Carolina Agricultural Experiment Station. In 1924 the USDA secured seed from Japan and planted it at the Arlington Experiment Farm in Virginia. Through the 1920s and 1930s it was promoted for erosion control and mine reclamation, and it was not widely used for pasture until the 1940s.

Then it was planted, repeatedly, on purpose — highway rights-of-way, dams, waterways, strip-mined land, wildlife habitat around reservoirs. K-State notes a later wave came in through the Conservation Reserve Program after the 1985 Farm Bill, because native grass seed harvested from rangeland often contained sericea seed and it "was not widely recognized as a potential weed at that time."

Kansas then reversed course in two steps. K-State records that sericea was declared a "county option" noxious weed in late 1988, and that the legislature declared it a statewide noxious weed on July 1, 2000. K-State adds a detail worth pausing on: sericea lespedeza is the first federally listed forage crop to be declared a noxious weed. Based on a 2006 Kansas Department of Agriculture inventory, Kansas had 598,000 acres identified with sericea lespedeza, and more than 73 counties reporting occurrence.

The statute itself named the species. Kansas Statutes Annotated 2-1314(b) listed "sericea lespedeza (Lespedeza cuneata)" alongside kudzu, field bindweed, Canada thistle and Johnson grass. That subsection expired on December 31, 2020, and the list is now set by the Secretary of Agriculture through rules and regulations under 2-1314(a) — so check the current regulatory list rather than the historic statutory one.

Two mechanics from that statute matter to you practically:

• Once a species is declared noxious statewide, it is noxious in every county, and landowners have a duty "to control the spread of and to eradicate" it using official methods.
• Separately, a board of county commissioners may list additional species for that county with the Secretary's approval. So a plant can be a legal problem in your county and not in the next one.

That county-level machinery is exactly what growers experience:

In my county Ceresa Lespedeza is considered a noxious weed, I don't know if this is the same as what you are talking about.

I spray Tordon to kill it, cause they sent me a letter. I don't know how it got there but I had to spray it.

— kshayharvester · HayTalk thread 11770

Hold that thought about Tordon — we come back to it in the control section, because it is the single most common mistake made with this plant.

Beyond Kansas, K-State's bulletin says sericea "may be considered as a noxious weed in Missouri, Nebraska, and Oklahoma." Regulatory lists change, and county lists sit underneath state lists. Confirm your own status with your state department of agriculture and your county weed director before you plant, buy, sell or move seed or hay.

Why it takes over — and why burning makes it worse

Sericea is not simply competitive; it is competitive through several mechanisms at once, and one of them makes the standard pasture-renovation tool backfire.

• Shading. Established plants restrict light reaching everything else. Cool-season grasses like Kentucky bluegrass survive the shade better; warm-season grasses like big bluestem survive but stay weak.
• Allelopathy. It releases chemicals from roots and leaches them from leaf residue that inhibit germination and growth of big bluestem, Indiangrass, Kentucky bluegrass, bermudagrass, fescue and ryegrass.
• Water use. K-State notes sericea's photosynthetic rate is only half that of alfalfa and it requires more water to produce foliage than other warm-season plants — effectively creating a drought for its neighbours.
• Poor nitrogen return. It is a legume, but with a low nitrogen fixation rate. What nitrogen it does supply is offset by the allelopathic compounds, and grass grown with it can end up lower in nitrogen and forage quality. You still have to fertilise.
• Seed. Individual stems may produce in excess of 1,000 seeds, at 300 to 850 pounds of seed per acre, with about 350,000 seeds per pound. Most seed is hard, with normal germination of only 10 to 20 percent — but K-State expects viability in soil of 20 years or longer.

Control: what works, what doesn't

This is the section most worth the reading time, because the intuitive choices are the wrong ones.

What does not work

• 2,4-D alone. K-State: sericea "has not been controlled with 2,4-D."
• Picloram + 2,4-D, or dicamba + 2,4-D. Described as achieving minimal kill. This is the Tordon problem from the quote above — a grower under a county enforcement letter, spraying a product that the state extension service says gives minimal kill on this species.
• Mowing, as a kill. Mowing reduces vigour if you cut close to the ground several times a year, and cutting late in the season when plants are building root reserves does the most damage. But mowing will not kill sericea, may damage desirable grasses, and leaves the seed bank intact.
• Burning alone. See above — it helps the plant.
• Season-long or rotational grazing with cattle alone. Cattle select the grass and leave the sericea, which hastens the invasion. Heavy grazing of the grass makes it worse.

What K-State says does work

• Triclopyr applied in June and July — described as giving excellent control.
• Metsulfuron applied in September — also described as giving excellent control.
• Meat goats, stocked to keep sericea grazed below a 3- to 4-inch height, to cut seed production. Cattle can run at the same time with the stocking rate adjusted down for reduced grass.
• An integrated sequence, which is what K-State actually recommends.

Note one gap: no herbicides have been labelled for seedling control, so the plan has to be built around established plants and around stopping seed.

Step 6 deserves emphasis for hay producers specifically: seed moves in animals and in hay. K-State attributes much of the original spread to animals and to movement of hay contaminated with sericea seed. If you are selling hay off an infested field, you are potentially selling the problem to your customer — and in a noxious-weed state that can carry legal weight. For the broader herbicide-and-carryover picture see our guide to weed control in hay fields, and note that roadsides are a classic reservoir, which we cover in the ditch hay and right-of-way guide.

The hay angle: why drying changes everything

Here is the fact that reframes sericea for anyone making hay, and it is not widely known.

Sericea's problem as forage is condensed tannins. Tannins bind proteins and make them unavailable for digestion; they make the plant unpalatable and reduce intake and digestibility. K-State notes tannin levels rise with plant maturity, high air temperatures and low rainfall. The USDA Forest Service's review adds that as plants mature, protein content and leaf-to-stem ratio fall while tannin content rises, and that grazing and haying are generally limited to young, tender plants under about 12 to 18 inches tall.

But then K-State states this directly: "Livestock readily consume hay containing sericea lespedeza, since field drying decreases the tannin concentration."

That single sentence explains a lot of contradictory farm experience. The same plant that cattle walk past in the pasture gets eaten in a bale, because the drying process lowers the compound that made it unpalatable. If you have sericea in a hay meadow, its feed value in the bale is better than its reputation on the hoof — provided you cut it young.

Two practical consequences:

• Cut early or don't bother. Past 12–18 inches you are baling stem, low protein and high tannin. Timing matters more with sericea than with most legumes.
• Do not move infested hay onto clean ground. This is the counterweight. Palatable hay that carries viable seed with a 20-year soil life is how sericea got to a lot of places. If you feed it, feed it where you already have the problem.

The goat and sheep research

The other half of sericea's split personality is a body of veterinary parasitology research that is genuinely solid, and which drives real demand — one grower in the corpus was weighing planting it precisely for that market:

I am considering growing AU GRAZER SERICEA LESPEDEZA. I know normal sericea Lespedeza is considered a noxious weed.

My reason for thinking of growing it is number one I have a strong goat market and from what I’ve been told goat people go crazy over it.

— Nate926 · HayTalk thread 100965

He is referring to a real cultivar. 'AU Grazer' was registered by J. A. Mosjidis of Auburn University in Crop Science in 2001. It sits in a family of improved sericea cultivars — 'Arlington', 'Serala', 'AU Lotan', 'AU Donnelly', 'AU Grazer', 'Interstate' — developed for low-input cattle forage, with stems that are shorter, finer, leafier and more numerous than common sericea, and bred with the intent of a more palatable forage with lower tannin levels.

The parasitology is where it gets interesting. Gastrointestinal nematode resistance to commercial dewormers is severe in the southern United States, and Haemonchus contortus — a blood-feeding abomasal worm — is the main killer of small ruminants there. Sericea's tannins turn out to be a liability that works as an asset:

• In a dose titration study (Terrill et al., Veterinary Parasitology, 2009), goats fed ground sericea hay at 25%, 50% and 75% of the diet had 45.3%, 66.3% and 74.5% lower faecal egg counts than controls fed bermudagrass hay after 21 days. By day 42 the 50% and 75% groups were 84.6% and 91.9% lower. The 75% group also had fewer abomasal worms.
• Pelleting does not destroy the activity (Terrill et al., 2007). Because heating during pelleting could plausibly deactivate condensed tannins, this was tested directly — pelleted sericea still reduced abomasal worms, primarily H. contortus, relative to bermudagrass-fed goats.
• In a leaf meal pellet trial (Kommuru et al., 2015), goats fed 75% sericea leaf meal pellets were compared against alfalfa pellets in a 28-day confinement study using artificially infected animals.

Two honest caveats before anyone reorganises a grazing plan around this. First, these are confinement feeding trials at high inclusion rates — 25% to 75% of the diet — not a claim that a pasture with some sericea in it will deworm a flock. Second, this is research, not a registered anthelmintic; it belongs in a parasite-management conversation with your veterinarian alongside faecal egg counts and refugia planning, not as a replacement for one.

If you are feeding hay to small ruminants, our guide on feeding net-wrapped hay to sheep and goats covers the handling side.

What the research does not settle

Two claims travel with sericea that we could not substantiate. A grazier in the corpus states both:

All of them have some (S.L. has almost too much) condensed tannans , which makes them non- bloating unlike many clovers and alfalfa.

The legumes with condensed tannans have been known to put more pounds on animals due to what they call bypass proteins/ amino acids.

— Holistic Grazer · HayTalk thread 11770

Both are widely repeated, and the biochemical mechanism is well established for condensed-tannin legumes generally. But the USDA Forest Service's literature review of this species — a document running to well over a hundred thousand words with primary citations throughout — does not discuss bloat at all, and we found no peer-reviewed source quantifying a bypass-protein benefit specifically for sericea lespedeza. Treat both as plausible and unproven for this plant rather than as established facts. If you are looking for a documented non-bloating legume comparison, our red clover guide is a better starting point.

Baling a field that has sericea in it

A practical note that only shows up from people who have actually done it: sericea's coarse, woody, densely branched stems do not feed like grass. It bunches.

the ony problem this machine is having is that it is bunching the hay in the mouth of the pickup

I am picking up sericia lespedeza.... every 50 feet, I have to stop and push the clogged up hay into the pickup bed so the fingers will catch it.

— Rockfoot · HayTalk thread 100087

If you are baling sericea-heavy windrows, expect to slow down, watch pickup feeding, and be careful about over-packing. The same stem characteristics that make it bunch at the pickup make it spring in the bale — which is a wrapping problem as much as a baling one. A dense, springy legume bale holds its shape only if the wrap holds tension on the shoulders, which is where cheap net wrap with poor edge-to-edge coverage tends to let go.

So: weed or forage?

The honest answer is that it depends on three questions, in this order:

1. What does your state and county say? This one is not a preference. In a noxious-weed jurisdiction, landowners carry a legal duty to control and eradicate, and official control methods may be prescribed. Check before anything else.
2. What are you feeding? The case is strongest for meat goats and sheep, where the tannins are the point and where the plant doubles as a control tool when stocked to hold it under 3 to 4 inches. It is weakest for cattle on pasture, which select against it and thereby help it spread.
3. What is your neighbour's exposure? Seed viable for 20 years or more, 350,000 seeds to the pound, moving in hay and in animals. Whatever you decide for your own ground, the containment question is real.

Where it already exists and you run small ruminants, sericea is a manageable resource — cut young, fed as hay, grazed hard. Where it does not exist and you run cattle, deliberately introducing it is a decision that generations of extension agents have spent careers undoing.

Frequently asked questions

Is sericea lespedeza a noxious weed?

In Kansas, yes — it was declared a county-option noxious weed in 1988 and a statewide noxious weed on July 1, 2000, making it noxious in every Kansas county with a landowner duty to control it. K-State notes it may also be considered noxious in Missouri, Nebraska and Oklahoma. Confirm current status with your state and county.

What is the difference between sericea lespedeza and annual lespedeza?

Sericea (Lespedeza cuneata) is a perennial that regrows from crown buds and is treated as invasive. Korean, common and Kobe lespedezas are introduced annuals, widely used in tamegrass pastures and considered valuable forage in southeast Kansas, southern Missouri and northeast Oklahoma. They are different plants with different management.

Will 2,4-D kill sericea lespedeza?

No. Kansas State University states sericea has not been controlled with 2,4-D, and that picloram plus 2,4-D or dicamba plus 2,4-D achieve only minimal kill. K-State reports excellent control from triclopyr applied in June and July, and from metsulfuron applied in September. Always follow current label directions.

Can livestock eat sericea lespedeza hay?

Yes, and generally better than they graze it. K-State states livestock readily consume hay containing sericea because field drying decreases tannin concentration. Cut young — grazing and haying are generally limited to plants under about 12 to 18 inches, since tannins rise and protein falls as the plant matures.

Does sericea lespedeza really work as a natural dewormer for goats?

Research supports an effect at high dietary inclusion. In a 2009 dose titration study, goats fed sericea hay at 50% and 75% of the diet had 84.6% and 91.9% lower faecal egg counts than controls by day 42. These were confinement trials, not a registered dewormer — use it alongside veterinary parasite management, not instead of it.

How long does sericea lespedeza seed last in the soil?

Kansas State University reports no firm data but expects viability of 20 years or longer. The seed is mostly hard and nearly impervious to water, with normal germination of only 10 to 20 percent. With about 350,000 seeds per pound and 300 to 850 pounds produced per acre, the seed bank is the hardest part of control.

Does burning control sericea lespedeza?

No — burning alone makes it worse. Spring burning removes dead growth but has no negative effect on established plants, and fire increases seed germination while creating the bare, sunlit seedbed seedlings need. Burning is useful only as preparation for herbicide applied to regrowth in the same year.

What is AU Grazer sericea lespedeza?

An improved forage cultivar registered by J. A. Mosjidis of Auburn University in Crop Science in 2001. Improved sericea cultivars have shorter, finer, leafier and more numerous stems than common sericea and were bred for better palatability and lower tannin levels. It remains the same species, so noxious-weed law still applies where it applies.

Noxious-weed designations, county lists and official control methods change and vary by jurisdiction; the summaries above are current to the sources cited rather than legal advice. Confirm your obligations with your state department of agriculture and county weed director, and follow current label directions for any herbicide. Nothing here is veterinary advice — discuss parasite management with your veterinarian.

Featured photo: Lespedeza cuneata by Dalgial, photographed in Incheon, Korea (the species' native range), released under CC BY-SA 3.0, via Wikimedia Commons.