Japanese clover
A low, wiry mat spreading through the thin, hard-packed patches of the lawn. It's common lespedeza — a summer-annual legume — and the good news is the timing is on your side: late July is right when to hit it, before it sets seed in late summer.
- Also called
- Common / annual lespedeza, Kummerowia striata (syn. Lespedeza striata)
- Type
- Warm-season annual — legume (fixes its own nitrogen)
- Loves
- Compaction · low fertility · scalped, thin turf
- Seeds
- Late summer → the seed bank replays each June
01What you're looking at
Read the weed as a symptom, not just a plant.
Lespedeza is a ground-hugging annual with small three-part leaves and a tough, almost wiry stem — it mats over bare and beaten-down ground rather than standing up in healthy turf. Where it's winning, it's telling you something about the soil: the lawn is compacted, under-fed, and probably mown too short. Because it's a legume, it fixes its own nitrogen, so it thrives exactly where grass is starved — a lawn deep in nitrogen deficiency — which is also the lever you'll use against it below.
The shade-and-moisture weed next door: Japanese stiltgrass.
02Knock it back now
Late July is good timing — you want it dead before it sets seed in late summer.
-
Spot-spray with a triclopyr broadleaf herbicide.
Look for one containing triclopyr (e.g. Ortho WeedClear, or a Weed-B-Gon Chickweed/Clover/Oxalis formula). Standard three-way
2,4-Dmixes are weak on lespedeza. Spray on a dry day, under about 85 °F, so you don't stress the grass at the same time. - Mow higher — 3.5 to 4 inches. Lespedeza hugs the ground and loves a scalped lawn. Raising the deck shades it out and lets the turf compete.
- Hit it with a nitrogen feed. The clover has the edge in nitrogen-poor soil — it makes its own. Fertilising the lawn removes that advantage and shifts the balance back to the grass. If the turf's gone pale and thin, that hunger is the real opening — see nitrogen deficiency for how much to feed and when.
Triclopyr spot-spray + raise the mower to ~4″ + a nitrogen feed — all while there's still summer left and before the plant seeds. That's the whole knock-back.
03Stop it coming back
Fix the conditions, not just this year's plants.
- This fallCore aerate. Compaction is lespedeza's favourite thing — relieving it is the single biggest prevention move. Overseed the thin spots at the same time so grass, not weed, fills the gaps.
- Next springPre-emergent, at forsythia bloom. Lespedeza germinates fairly early, so time the pre-emergent to when the forsythia flowers — the classic soil-temperature cue — to catch it before it sprouts.
04If it comes back next June
Expect an encore — and don't read it as failure.
If it dies off and then reappears next June, that's normal. It's an annual, so what you're seeing is the seed bank replaying, not the treatment failing. A couple of seasons of the routine above — knock-back, feed, aerate, pre-emergent — usually breaks the cycle by starving the seed bank and thickening the turf that would otherwise leave it room.