Weed Control
Dallisgrass: How to Identify and Control It in a Lawn
Quick answer
Dallisgrass is a perennial clumping grass of southern lawns with no practical selective control for homeowners. The realistic route is spot treatment with a non-selective product followed by replugging or resodding, plus a spring pre-emergent to cut seedlings. Expect repeat passes.
Dallisgrass is the weed southern lawn owners ask about most and get the least satisfying answer to. It is a perennial, so it returns from short thick rhizomes every year. It is a grass, so broadleaf products are irrelevant. And the professional chemistry that once handled it, MSMA, is now restricted in most states to golf courses, sod farms and highway rights of way rather than home lawns.
What is left is honest but laborious: prevent seedlings, spot treat established clumps and repair the holes. Plan the repair with the lawn size calculator, since replugging and resodding are sold by area.
On this page
How do I identify dallisgrass?
| Trait | Dallisgrass |
|---|---|
| Weed type | Grassy weed |
| Life cycle | Perennial; short rhizomes survive winter and widen the clump each year |
| Season | Warm season; grows hardest in summer heat |
| How it spreads | Short thick rhizomes expanding the clump, plus abundant seed |
| Growth habit | Coarse clumps that expand outward in rings, often with a dying center in older clumps |
| Leaf | Wide, light green blades with a prominent white midrib, coarser than surrounding turf |
| Seedhead | Tall stalk carrying 3 to 5 finger-like branches, with seeds in four rows fringed with fine silky hairs |
| Growth rate | Faster than the lawn, so clumps stand tall within days of mowing |
| What it says about the lawn | Moist fertile ground, thin turf, and often years of seed production nearby |
Crabgrass is the usual confusion, but crabgrass is an annual that dies at frost and sprawls flat rather than forming expanding perennial clumps. If the clump returns in the same place each year, it is not crabgrass.
Why is dallisgrass so hard to control?
Three things at once. It is perennial, so any approach aimed at annual grassy weeds misses. It is a grass growing in grass, which leaves almost no chemical selectivity to exploit in a residential setting. And MSMA, the organic arsenical that was the classic answer, carries restricted use patterns that in most states exclude home lawns entirely.
The rhizomes add the final difficulty. Pulling or digging a clump usually leaves rhizome pieces that regenerate, so partial removal produces several smaller clumps. If you dig, take a wide margin and remove the whole root mass, then fill and repair the hole immediately so nothing else colonizes it.
Prevention deserves more attention than it usually gets. A spring pre-emergent will not touch established clumps, but it reduces the seedlings that create next year's clumps. Timing guidance is in when to apply pre-emergent.
How do I get rid of dallisgrass?
Decide between removal and management. Removal means creating bare spots on purpose and repairing them, which is the only home-lawn route that reliably works.
| Method | When | What it involves |
|---|---|---|
| Non-selective spot treatment | Growing season, on actively growing clumps | Glyphosate kills the clump and the turf around it. Treat deliberately, then repair the hole. |
| Repeat the spot treatment | On regrowth, per label | Rhizomes often survive a single application, so a second pass on regrowth is normal. |
| Replug or resod | After the label replanting interval | Bare spots refill with weeds if left open. Plugs or sod restore warm-season turf faster than seed. |
| Spring pre-emergent | Before soil warms in spring | Reduces new seedlings. It does nothing to established clumps, so treat it as prevention only. |
| Dig with a wide margin | Small isolated clumps, moist soil | Remove the entire root and rhizome mass, then fill and repair. Partial digging creates several clumps. |
| Mow and manage | Ongoing, if removal is not worth it | Frequent mowing keeps clumps less obvious and limits seed, but it does not reduce the stand. |
| Full renovation | For heavily infested lawns | Kill everything, wait out the label interval, then resod. Sometimes the cheapest honest answer. |
MSMA is restricted in most states to sites such as golf courses, sod farms and highway rights of way, and it is not a home-lawn option. Any advice suggesting otherwise is out of date.
Which products are relevant?
Roundup Weed and Grass Killer4 Concentrate, 1 gal is the non-selective concentrate for spot treatment, rainproof in about 30 minutes with replanting 1 to 30 days later per the label. For prevention, Quali-Pro Prodiamine 65 WDG Pre-Emergent Herbicide, 5 lb is sprayable prodiamine and Scotts Halts Crabgrass and Grassy Weed Preventer, 20.12 lb is the granular option at 10,000 sq ft, both aimed at seedlings rather than clumps.
For repair, southern lawns generally go with plugs or sod rather than seed. SodPods St. Augustine Seville Grass Plugs, 64 Count supplies 64 farm-grown 3 by 3 inch plugs, listed as covering 144 sq ft at 18 inch spacing once mature and unable to ship to CA or AZ. ZoysiaPlug.com Zoysia Plugs, 100 Large Plugs provides 100 mature zoysia plugs for roughly 100 sq ft. On bermuda lawns, Scotts Turf Builder Grass Seed Bermudagrass, 4 lb seeds 1,330 sq ft in late spring or early summer. Background on each grass is in St. Augustinegrass, zoysiagrass and bermudagrass.
What gear helps with dallisgrass?
A sprayer with a tight pattern for treating clumps without widening the damage, plus repair material. Precision is the whole point here.
Chapin 16200 2-Gallon Pump Sprayer
$26.44A 2 gallon pump sprayer with an adjustable cone nozzle that dials down to a narrow pattern, which limits how much good turf a non-selective treatment takes with it.
Best for: treating individual clumps
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SodPods St. Augustine Seville Grass Plugs, 64 Count
$109.98Sixty-four farm-grown 3 by 3 inch Seville plugs, listed as covering 144 sq ft at 18 inch spacing once mature; it cannot ship to CA or AZ.
Best for: repairing St. Augustine lawns, which do not grow from seed
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Scotts Halts Crabgrass and Grassy Weed Preventer, 20.12 lb
$49.02A granular pre-emergent covering 10,000 sq ft with no fertilizer mixed in, applied to a dry lawn to reduce next year seedlings.
Best for: spring prevention with a spreader
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We did not test these products in person. Picks are researched from manufacturer specifications and owner manuals, engine and safety certifications where they apply, warranty terms, public recall records, and the recurring themes in verified owner reviews. We favor established brands with large review counts and parts support, match each pick to a real yard size or task, and place it in the tier where its price and capability actually belong.
Frequently asked questions
Is there a selective herbicide for dallisgrass in home lawns?
Not a practical one. Dallisgrass is a perennial grass growing among desirable grasses, which leaves little selectivity to exploit, and MSMA, the product historically used against it, is now restricted in most states to sites such as golf courses, sod farms and highway rights of way. Homeowners are left with non-selective spot treatment followed by repair, plus pre-emergent to reduce seedlings.
How is dallisgrass different from crabgrass?
Dallisgrass is a perennial that returns from rhizomes in the same spot every year and forms coarse clumps expanding in rings, often with a dying center. Crabgrass is a summer annual that dies at frost and sprawls flat in a star pattern. Seedheads differ too: dallisgrass carries 3 to 5 branches with seeds in four fringed rows, while crabgrass spreads finger-like spikes.
Can I dig dallisgrass out?
Yes for isolated clumps, if you take a wide margin and remove the entire rhizome mass. Partial digging leaves pieces that regenerate, which typically turns one clump into several. Fill and repair the hole the same day with plugs, sod or seed appropriate to your grass, because bare ground in a southern lawn is colonized quickly by whatever weed seed is nearby.
Researched, not professional advice. This page is compiled from published specifications, manuals, labels and owner-review consensus, not hands-on testing. Follow the manufacturer's instructions and product label, and consult a qualified professional where safety, chemicals, fuel or structures are involved. As an Amazon Associate we earn from qualifying purchases.