Weed Control
Foxtail Grass: How to Identify and Kill It in a Lawn
Quick answer
Foxtail is a summer annual grass named for its bristly cylindrical seedhead. Treat it like crabgrass: a pre-emergent before soil holds 55 F at 2 inches, quinclorac on plants already up, and mowing at 3 to 4 inches so seedlings never get the light they need.
Foxtail is named for the seedhead, a dense bristly cylinder that looks like a fox tail or a bottle brush. Green, yellow and giant foxtail all show up in lawns, and for control purposes they behave the same way: summer annuals that germinate in warming spring soil, seed heavily in summer, and die at frost.
Because the life cycle matches crabgrass almost exactly, the same pre-emergent timing and many of the same products apply. Foxtail is most common in new lawns, recently disturbed ground and thin sunny areas. Plan the reseeding that closes those gaps with the grass seed calculator.
On this page
How do I identify foxtail?
| Trait | Foxtail (green, yellow and giant) |
|---|---|
| Weed type | Grassy weed |
| Life cycle | Summer annual; dies at frost and returns from seed |
| Season | Warm season; germinates in spring as soil warms, seeds through summer |
| How it spreads | Seed only, in very large numbers |
| Seedhead | Dense bristly cylinder at the top of an upright stem, like a bottle brush. Green foxtail nods, yellow foxtail stands upright |
| Ligule | A fringe of hairs where the blade meets the sheath, not a membrane, which separates it from many lawn grasses |
| Leaf | Flat blades, with yellow foxtail showing long silky hairs near the base of the blade |
| Growth habit | Upright clumps rather than the flat star of crabgrass |
| What it says about the lawn | Thin or new turf, disturbed soil, compacted areas and sunny edges |
Foxtail grows upright in clumps while crabgrass sprawls flat. The seedheads settle it: bristly cylinder means foxtail, spread fingers mean crabgrass.
Why do I have foxtail in my lawn?
Disturbed soil is the usual answer. Foxtail seed is abundant in field soil, imported topsoil and construction fill, and it germinates readily on open ground. That is why new lawns, regraded areas and repaired trenches often come up thick with foxtail in their first summer while the rest of the yard has none.
After that it persists wherever turf stays thin: sunny edges, compacted strips and scalped high spots. The corrective work is ordinary lawn care, not exotic chemistry. Mow at the top of the range for your grass, feed on a real schedule, and overseed the thin areas. See the mowing height chart and how to overseed a lawn.
What kills foxtail without killing grass?
Foxtail is a grass, so broadleaf products do nothing. The workable controls are a pre-emergent barrier in spring and quinclorac on plants that got through.
| Method | When | What it involves |
|---|---|---|
| Pre-emergent herbicide | Before soil holds 55 F at 2 in for several days | Prodiamine or dithiopyr, watered in per the label. Same window as crabgrass, and the main preventive control. |
| Split application | Later in the label window | Extends the barrier through a long germination period in warm regions. |
| Quinclorac post-emergent | On actively growing plants | Labeled for foxtail as well as crabgrass, on warm and cool-season turf. Follow the label on newly seeded areas. |
| Raise mowing height | Every mowing | Foxtail seedlings need light at the soil surface. A taller canopy denies it. |
| Overseed thin and new areas | Late summer to early fall | Turf density is what keeps a repaired or new area from refilling with foxtail next year. |
| Hand pulling | Before seedheads mature | Practical in small numbers. Remove plants with seedheads rather than dropping them on the lawn. |
| Let frost finish it | Late season | Foxtail is an annual. Spraying in autumn kills a plant that is already finishing. |
Bag clippings while foxtail is seeding. Mowing through mature seedheads spreads seed efficiently across the rest of the lawn.
Which products handle foxtail?
BASF Drive XLR8 Crabgrass Killer Concentrate, 64 oz is the quinclorac post-emergent that names foxtail on its label and works on both warm and cool-season turf with up to 30 days of residual. For prevention, Scotts Halts Crabgrass and Grassy Weed Preventer, 20.12 lb lists foxtail alongside crabgrass and spurge across 10,000 sq ft, and Quali-Pro Prodiamine 65 WDG Pre-Emergent Herbicide, 5 lb is the sprayable prodiamine for people who prefer to mix their own and time it precisely.
Broadleaf concentrates such as Ortho WeedClear Weed Killer for Lawns Concentrate, 1 gal will not touch foxtail, because it is a grass. Roundup Weed and Grass Killer4 Concentrate, 1 gal kills it along with the lawn, which only makes sense on a full renovation followed by seeding with something like Pennington Kentucky 31 Tall Fescue Grass Seed, 40 lb, rated for up to 8,000 sq ft.
What gear helps with foxtail?
A spreader for the spring barrier, a sprayer for the plants that beat it, and seed for the thin ground that invited it. Tiered picks are in the best crabgrass preventers.
Scotts Turf Builder EdgeGuard DLX Broadcast Spreader
$94.97A pre-calibrated broadcast spreader with an edge shield, holding up to 15,000 sq ft of product for an even pre-emergent pass.
Best for: lawns up to about a third of an acre
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Chapin 16200 2-Gallon Pump Sprayer
$26.44A 2 gallon poly pump sprayer with an in-tank filter and nitrile seals, enough for treating clumps without mixing a backpack.
Best for: spot-treating foxtail clumps
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Pennington Kentucky 31 Tall Fescue Grass Seed, 40 lb
$67.00An economical drought-resistant tall fescue covering up to 8,000 sq ft, suited to the large disturbed areas where foxtail appears.
Best for: seeding new or regraded lawns
Check price on AmazonHow we chose
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
How is foxtail different from crabgrass?
Growth habit and seedhead. Foxtail grows upright in clumps and carries a dense bristly cylinder like a bottle brush, while crabgrass sprawls flat in a star pattern with seedheads spread like fingers on a hand. Both are summer annuals that die at frost, and both respond to the same pre-emergent timing, so a product naming crabgrass usually names foxtail too.
Is foxtail dangerous to dogs?
The mature seedheads are a real veterinary concern. Their barbed bristles work into paws, ears, noses and eyes and migrate under the skin, and they do not break down, so they often need removal by a vet. Mow before seedheads mature, bag those clippings, and check dogs after they run through tall grass or field edges where foxtail is heavy.
When should I apply pre-emergent for foxtail?
The same window as crabgrass: before soil holds about 55 F at 2 inches for several consecutive days. Foxtail is a summer annual germinating as soil warms in spring, so a barrier in place before that point prevents the whole generation. Measure soil temperature rather than following a date, and consider the split application many labels allow for longer coverage.
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.