Dallisgrass Lawn Weed (Control Guide)

Dallisgrass is a tough, warm-season perennial that can return after mowing because its crown survives below the cut. First confirm the weed and your lawn species, then choose a treatment labeled for both. Prevent seedheads, follow the label, and repair bare spots after control. Preemergence products may stop seedlings, but they will not kill established plants.

When coarse, spreading clumps keep coming back, mowing can make the lawn look neater without solving the problem. The key is to identify the grass correctly and match the treatment to your turf. A product that controls dallisgrass in one lawn may injure another.

I approach each patch as two jobs: control the weed, then protect or restore the desirable grass around it. That means checking the plant, reading the label, and planning follow-up before treating.

Identification, Product Selection & Site Safety

Correct identification and turf identification come first. Dallisgrass (Paspalum dilatatum) is a warm-season perennial grass that forms coarse clumps. Its crown can regrow after mowing. Before choosing a product, check the plant and lawn species, then confirm that the label allows the intended use.

Dallisgrass often stands out as a coarse, uneven clump in a finer lawn. It can spread by seed and short rhizomes, which are underground stems. Its seedheads rise above the leaves and bear several branches with small spikelets. Appearance varies, so do not rely on one feature alone.

Rule out lookalikes

Crabgrass is usually a summer annual: it grows from seed and dies with frost. Dallisgrass is perennial and can return from the same crown. Other coarse grasses can also be mistaken for it. If you are unsure, photograph the leaves, base, and seedhead, then ask a local university extension service or turf professional to confirm it.

Mark the suspect clumps and check whether they return from the same spots. Also identify the desirable lawn grass, such as bermudagrass, zoysiagrass, or tall fescue. A product safe for one species may harm another.

Match the herbicide to the lawn

Selective herbicides target certain weeds while allowing listed turf species to tolerate the treatment when used as directed. Selectivity is not universal. For example, some products containing foramsulfuron list dallisgrass control in bermudagrass. That does not establish that they are safe for other lawns.

Read the full product label before buying or applying anything. Confirm that it lists dallisgrass, your exact turf species, and the site where you plan to use it. Check local pesticide rules as well. If no suitable selective product is labeled, consider removing the plant or renovating the small area instead.

Protect people, pets, and turf

Wear the personal protective equipment (PPE) listed on the label. Do not treat drought-stressed or otherwise stressed turf. Check the wind and rain directions on the product label, and keep people and pets off treated areas for the stated time.

Measure the product and calibrate the applicator to deliver the label rate. Calibration means checking how much spray your equipment applies over a known area. This helps prevent underdosing, excess product, and uneven coverage. Avoid spray drift and overlapping passes.

Dallisgrass Treatment & Turf Repair

Treatment should match the size of the patch and the label. Use only a product labeled for both dallisgrass and your lawn species. Apply it at the labeled rate and timing, then wait for the label’s stated response period before judging the result or treating again.

Start by mapping the clumps. A quick sketch or phone photo helps you find each spot later and see whether it is shrinking, returning, or producing seedheads. Remove seedheads before seed matures when practical, but remember that this only limits seed production. It does not kill the established crown.

For a labeled selective herbicide:

• Read the full label, including restrictions and repeat-treatment directions.
• Check that the lawn is not drought-stressed or otherwise under stress.
• Measure the lawn area and product amount as the label requires.
• Calibrate the sprayer and apply evenly, without overlap or drift.
• Keep people and pets away for the interval stated on the label.
• Recheck the patch after the response period listed on the label.

Do not guess at a rate or repeat interval. Both can vary by product, turf species, and local rules. A second application is appropriate only if the label allows it and gives directions for when to apply again.

If selective control is not suitable, remove a small plant by digging out the crown and roots. The crown is the dense base where the leaves meet the roots; pieces left behind may regrow. Avoid spreading fragments into nearby soil, and fill the hole with suitable soil and seed or sod that matches the lawn.

Glyphosate is nonselective. It can kill desirable turf as well as dallisgrass, so it is not a broadcast lawn treatment. If a carefully shielded spot application is used according to its label, expect to repair the dead area. A bare patch can be vulnerable to erosion and reinvasion, especially if it stays open.

Worked treatment scenarios

These examples show how to choose a method; they are not reports of measured product results. Always follow the label for your own site.

A homeowner finds several clumps in bermudagrass. After confirming both the weed and turf, they find a product whose label lists dallisgrass and bermudagrass. They follow the label, mark the spots, and check them again after the stated response period.

Another homeowner finds one clump in a lawn species not listed on the available selective product. Rather than assume the treatment is safe, they dig out the crown and roots, then repair the spot. If removal leaves a large bare area, they can plan a broader renovation instead of risking injury across the lawn.

Follow-Up, Mowing & Control Assessment

Follow-up helps you tell whether treatment worked and catch new growth before it spreads. Check the same marked spots after the product’s stated response period. Look for living leaves or new shoots from the crown, and note any damage to nearby turf before deciding what to do next.

Mowing can keep seedheads from maturing if timed appropriately, but it does not eradicate dallisgrass. The low-growing crown can survive the cut and send up new leaves. Set mowing height for your turf species, and avoid cutting stressed grass too short.

Use a simple record for each patch:

• Location and approximate patch size.
• Date treated or removed.
• Product name and the label’s instructions followed.
• Changes in the weed and nearby turf at each check.

If the label permits another treatment, follow its stated interval and conditions. If the patch remains active and no repeat is allowed, do not apply extra product on your own schedule. Recheck your identification, consult local extension guidance, or switch to a labeled removal or renovation plan.

Prevention & Seasonal Care

Prevention aims to reduce new seedlings and limit spread while keeping the lawn dense. Dallisgrass can spread by seed and short rhizomes, so remove seedheads before seed matures when possible. A healthy lawn also leaves less open ground for weeds to establish.

Preemergence herbicides work on some germinating seedlings before they emerge. They do not kill established dallisgrass crowns. Use one only if its label covers the target and lawn species, and follow any directions that affect seeding or turf repair.

Keep an eye on lawn edges, thin areas, and places where clippings or soil may carry seed. Maintain the mowing height and watering practices recommended for your turf species. Local extension services can help with region-specific timing, since warm-season weeds and lawn growth do not follow the same calendar everywhere.

A useful seasonal routine is to inspect, mark, and act before seed matures. After control, repair bare areas promptly with turf suited to the site. Then keep checking the old patch and nearby ground rather than assuming one treatment ends the problem.

FAQ: Dallisgrass Control

These quick answers cover common treatment choices and follow-up questions. The right action depends on a confirmed weed identification, the lawn species, and the product label. When those details do not line up, avoid applying a herbicide until you have a suitable, legal option.

Does mowing kill dallisgrass?
No. Mowing may remove seedheads, but the perennial crown can survive and regrow.

Will preemergence herbicide kill established dallisgrass?
No. Preemergence products may prevent some seedlings, but they do not kill established crowns.

Can I use the same selective herbicide on every lawn?
No. Permitted uses and turf safety depend on the product label and lawn species. Check both before treating.

Is foramsulfuron safe for all lawn grasses?
No. Some product labels allow use for dallisgrass in bermudagrass. Do not assume that use is safe for another turf species.

Can I use glyphosate on dallisgrass in my lawn?
Glyphosate is nonselective and can kill desirable turf it touches. A spot treatment may require careful shielding and later lawn repair.

Should I treat dallisgrass when the lawn is dry or stressed?
Do not treat drought-stressed or otherwise stressed turf. Follow the product label for suitable conditions.

When can I repeat a herbicide application?
Only when the label allows another application, and only at the stated interval and rate. There is no universal repeat schedule.

How do I know if treatment worked?
Recheck the marked patch after the label’s stated response period. Look for living growth or new shoots from the crown.

Should I remove seedheads?
Removing them before seed matures can reduce new seed, but it will not kill the plant or its crown.

What should I do after removing a clump?
Remove the crown and roots as fully as practical, then fill and repair the bare spot with turf suited to your lawn. Keep checking for regrowth.

(This article was written by one of our staff writers, Victor Dempsey. Visit our Meet the Team page.)