What Is Dallisgrass? (Weed Identification)
Dallisgrass (Paspalum dilatatum) is a coarse, warm-season perennial grass that grows in clumps and can stand about 1.5–5 feet tall when its seed stalks are present. Look for broad leaves, a short membrane at the leaf collar, and usually three to five fingerlike seedhead branches. Confirm several traits before removing or treating it.
To identify dallisgrass, start with the whole plant, not a single clue. Check how it grows, examine the leaf where it meets the stem, and look for mature seedheads if present. Then decide whether it is growing in lawn turf, an ornamental bed, or pasture, since the suitable control method depends on the site.
I use that sequence because many grasses look alike, especially before they produce seedheads. A careful check can help prevent you from pulling a desirable grass or applying a product where it does not belong. The field scenarios below are illustrative, not reports of specific properties.
Identification and Site-Safety Preparation
Dallisgrass is a warm-season perennial bunchgrass, meaning it can return from the same plant in later growing seasons and often forms a noticeable clump. It is commonly about 1.5–5 feet tall when seed stalks are present, though regular mowing can keep it shorter. Confirm its identity with several plant features.
What does dallisgrass look like?
Dallisgrass has coarse, broad, flat leaves that are typically about 4–10 millimeters wide. A prominent midrib, the raised central line in a leaf, may be easy to see. Leaf width helps narrow the possibilities, but it is not enough by itself to identify the plant.
Look for these features together:
- Growth habit: A warm-season perennial that often grows as a clump. A mature clump may be conspicuous in otherwise even turf.
- Height: Seed stalks commonly reach about 1.5–5 feet, or 0.5–1.5 meters. Mowing can make the plant look much shorter.
- Leaf blades: Broad and flat, typically about 4–10 millimeters wide, with a noticeable midrib.
- Leaf collar: The point where the leaf blade meets the stem. Dallisgrass has a short, membranous ligule, usually around 2–4 millimeters long. A ligule is a small flap or fringe at this junction; the collar may also have hairs.
- Seedhead: Usually three to five fingerlike branches, called racemes, near the top of a stalk. Small spikelets, or seed-bearing units, sit in two rows along each branch. Seedheads may have a purple tint.
A seedhead can make identification easier, but color varies and should not be treated as proof. Likewise, not every dallisgrass plant will be tall or flowering when you inspect it.
How can I check the plant safely?
A close inspection means looking at the leaf collar and, when possible, a mature seedhead. Before you start, note the site and nearby plants. Wear gloves and closed-toe footwear, and avoid handling or spreading seedheads if you suspect they are affected by ergot fungus.
First, decide whether the plant is in lawn turf, an ornamental planting, or pasture. Note desirable plants nearby and check whether water is close to the area. These details matter if you later consider a control product, because its label sets where and how it may be used.
If you can, examine a leaf where it joins the stem. The ligule may be easier to see if you gently part the leaf sheath, the lower portion that wraps around the stem. Do not rely on one detail: compare the clump, collar, leaves, and seedhead as a set.
Field Inspection and Dallisgrass Control
Once you have checked the plant, choose a response that fits both the infestation and the site. A single clump in a small area may be practical to dig out. A larger patch may need a product labeled for that exact setting, with close attention to its restrictions and directions.
How do I distinguish dallisgrass from similar grasses?
Look at growth form and seedhead structure as well as leaf traits. Several lawn grasses have broad leaves or branched seedheads, so no single feature is a reliable test. Use the comparison as a screening aid, then check the plant’s collar and other features before acting.
| Possible match | Clues to compare | What the clue does and does not tell you |
|---|---|---|
| Dallisgrass | Coarse clump; broad leaves; usually 3–5 fingerlike racemes; short, membranous ligule | The combination supports identification, but confirm more than one feature. |
| Crabgrass | Often spreads low across the soil and may root at joints; seedheads have fingerlike branches | Fingerlike branches can look similar. Growth habit and the full plant matter; branch count alone is not decisive. |
| Bahiagrass | Seedhead often has two main branches in a V shape | The typical shape differs from dallisgrass, but inspect the plant rather than relying only on the seedhead. |
| Another lawn grass | May have broad leaves or form a clump | Leaf width alone cannot confirm dallisgrass. Check the collar, growth habit, and seedhead if present. |
These are useful comparisons, not a complete field key. If the plant remains uncertain and treating it could harm valued turf or ornamentals, wait for a clearer seedhead or ask a local extension office or qualified lawn professional to confirm it.
What should I do about an identified clump?
For an isolated plant, dig around the crown, the compact base where stems meet roots, and remove as much of the root mass as practical. Work carefully so you do not scatter seed or damage nearby plants. Check the area afterward for pieces or regrowth.
For a larger infestation, do not assume that a product is safe just because it is sold for weeds. Use only a control product labeled for the specific site, such as the relevant turf or landscape setting, and follow all label directions. The label may limit use by turf species or other site conditions.
Never apply a nonselective herbicide over desirable turf or ornamentals unless the label explicitly allows that use. A nonselective herbicide can injure or kill plants it contacts, including plants you intend to keep. If the label does not clearly cover your site and intended use, do not apply the product there.
Field scenarios: matching the response to the site
These brief scenarios show how the same identification steps can lead to different choices. They are examples for decision-making, not a guarantee that one method will work in every lawn or landscape.
- One clump in a small lawn: Confirm several traits, then consider digging out the crown and as much root mass as practical. Check for regrowth and seedlings later.
- Several clumps among valued ornamentals: Identify the grass before acting. Digging may allow more control around nearby plants; any product must be labeled for that landscape site and used as directed.
- A broad patch in pasture: Confirm the plant and consider livestock safety. If seedheads may be affected by ergot, keep livestock away from suspect material and seek local agricultural or veterinary guidance.
Tool Cleaning and Follow-Up Monitoring
Removal is not the end of the job. Soil and seed can cling to shoes, gloves, and tools, then move to another part of the yard. Clean equipment before leaving the infested area, and revisit the site to look for regrowth or new seedlings.
How should I clean tools after removal?
After digging, remove visible soil and plant material from the tool before using it elsewhere. Pay attention to joints, edges, and other places where soil or seeds can stick. Clean footwear and gloves too, especially if you are moving into an uninfested lawn or planting bed.
This simple step helps limit the movement of seed and soil. It does not replace follow-up checks: a plant may regrow, and new seedlings may appear later. Dispose of removed material in a way that follows local yard-waste rules, and avoid spreading mature seedheads around the property.
What should I watch for after control?
Recheck the treated spot for a returning clump, surviving shoots, or small new plants. If you dug the plant, look for regrowth from the crown or remaining roots. If you used a control product, follow its label for any repeat application, timing, or site restrictions; do not invent a schedule or apply more than the label allows.
Seasonal Recheck and Seedhead Management
Dallisgrass is a warm-season grass, so its appearance changes as it grows. A plant may be less obvious when short or mowed and easier to recognize once seed stalks form. Recheck the site during active growth and again when seedheads are visible, while keeping livestock away from seedheads that may be contaminated.
Why do seedheads matter?
Seedheads help with identification because dallisgrass usually has three to five fingerlike racemes, with spikelets arranged in two rows on each raceme. They can show purple coloration, but color alone does not confirm the species. Comparing the seedhead with the clump, leaves, and ligule gives a stronger identification.
There is also a safety concern in pasture. Dallisgrass seedheads infected with ergot fungi can contain toxic compounds. If seedheads look suspect or livestock may have eaten them, keep animals away from the material and contact local agricultural or veterinary experts for guidance. Do not rely on appearance alone to assess exposure.
When should I recheck the area?
Check again during the warm growing season and whenever you notice a coarse clump or new seed stalk. The exact timing varies with local conditions and mowing, so use what you see at the site rather than a fixed calendar date. Look for both surviving plants and seedlings.
If the grass is still present, confirm its identity again before repeating a treatment. For any herbicide, use only label-directed timing and methods. Clean tools after each removal and avoid carrying soil or seed into areas where dallisgrass is not present.
Conclusion and FAQ
Dallisgrass is best identified by a combination of traits: a coarse perennial clump, broad leaves with a prominent midrib, a short membranous ligule, and a seedhead that usually has three to five fingerlike branches. Confirm the plant before controlling it, match the method to the site, and follow up for regrowth or seedlings.
Is dallisgrass a perennial?
Yes. It is a warm-season perennial bunchgrass that can return from the same plant in later growing seasons.
How tall does dallisgrass get?
It commonly reaches about 1.5–5 feet, or 0.5–1.5 meters, when seed stalks are present. Mowing can keep it shorter.
What do dallisgrass leaves look like?
The leaves are broad and flat, typically about 4–10 millimeters wide, with a prominent midrib. Leaf width alone cannot confirm the species.
How many branches does a dallisgrass seedhead have?
It usually has three to five fingerlike racemes near the top of the stalk. Check other plant features too, because seedheads can resemble those of other grasses.
Can I identify dallisgrass by purple seedheads?
No. Seedheads may show purple coloration, but color varies and is not enough for identification. Compare the seedhead with the plant’s growth habit, leaves, and collar.
What is the ligule on dallisgrass?
The ligule is a small structure where the leaf blade meets the stem. Dallisgrass usually has a short, membranous ligule about 2–4 millimeters long.
Can I remove one dallisgrass plant by hand?
For an isolated plant, you can dig around the crown and remove as much of the root mass as practical. Recheck the spot for regrowth.
Can I spray dallisgrass in my lawn?
Only use a product labeled for that specific lawn site and turf type, and follow its directions. Do not apply a nonselective herbicide over desirable plants unless the label permits that use.
Is dallisgrass dangerous to livestock?
Dallisgrass seedheads infected with ergot fungi can contain toxic compounds. Keep livestock away from suspect seedheads and seek local agricultural or veterinary guidance if exposure is possible.
What should I do after removing dallisgrass?
Clean soil and plant material from tools, gloves, and footwear before moving to uninfested areas. Recheck the site for regrowth and new seedlings.
(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)
