Lawn Care · Crabgrass
Crabgrass dies every fall. The natural fix is making sure it doesn’t come back.
To get rid of crabgrass naturally, pull young plants by hand before they set seed, then stop next year’s seeds from sprouting by mowing high (about 3 inches) and keeping the lawn thick, overseeding thin spots in late summer. Crabgrass is a summer annual that frost kills, so you are not fighting old plants, only new seedlings. Vinegar, boiling water and clove oil burn the leaves but also burn your grass, corn gluten meal gives partial control at best, and we found no research showing baking soda or cola works.
LIFE CYCLE
Summer annual, killed by frost
SEEDS PER PLANT
Up to about 150,000
SEEDHEADS FORM
July through September
BEST NATURAL CONTROL
Mow about 3 in, keep turf dense
Why crabgrass needs a different natural plan
Most “natural weed killer” advice is written for perennial weeds with deep roots. Crabgrass is not one of them. It is a summer annual: it sprouts from seed in spring and early summer, grows through the heat, forms seedheads from July through September, and turns reddish-brown and dies after the first fall frost, according to Penn State Extension. Next year’s crop comes entirely from the seed this year’s plants dropped.
That seed supply is the whole problem. UMass Extension says one plant can make up to 150,000 seeds and can still produce seed when mowed as low as half an inch.
So a natural plan has two jobs. This year, keep the plants you have from seeding. Next year, make the lawn too thick and shady for the new seeds to get going. If you are not sure the grassy weed in your lawn is crabgrass, check our crabgrass identification guide first. Colorado State notes that a lot of what people call crabgrass is really a perennial grass like quackgrass or tall fescue, which none of this will fix.
Pull young crabgrass before it seeds
Penn State says a few plants can simply be pulled or lifted out with a trowel. The timing is what makes it count:
- When. Pull while plants are young, before they flower and set seed. That is the guidance from UC IPM’s lawn weed guide, and for crabgrass it means late spring through midsummer, before the finger-like seedheads show up.
- Soil moisture. Oregon State Extension says to pull when the soil is moist so the roots come out with the plant. A day after rain or watering is ideal.
- How. Grip the plant at the base, where the stems spread out from the center, and lift the whole clump. Bigger clumps come out more easily with a hand weeder slid underneath. Our crabgrass removal tool guide compares the options.
- Fill the hole. UC IPM advises refilling dug-out spots with clean soil.
- Dispose of it. Oregon State says to get pulled plants off the lawn so they can’t reseed. Bag them rather than leaving them in a pile.
Mow high and keep the lawn thick
This is one of the most effective natural crabgrass controls, and it costs nothing. Because crabgrass seed needs light, taller grass that shades the soil surface stops much of it from sprouting. The extension numbers line up:
- Penn State: mowing regularly at about 3 inches deprives emerging seedlings of light and reduces the population.
- Purdue: mow at 2.5 to 3 inches depending on species; mowing below that range increases crabgrass. Purdue shows a heavy crabgrass stand in a Kentucky bluegrass lawn mowed at 1 inch.
- University of Minnesota: raise the mower to at least 3 inches to cut the sunlight reaching the soil.
- Oregon State: about 3 to 4 inches.
Those heights fit cool-season lawns like bluegrass and tall fescue. Bermuda and zoysia are mowed lower, so in a warm-season lawn, stay at the top of your grass’s normal range instead.
Height works best alongside density. Purdue’s cultural plan for cool-season lawns is to water deeply and infrequently (light, frequent watering favors crabgrass), apply 2 to 4 lb of nitrogen per 1,000 sq ft a year with 60 to 100% of it split between a September and a November feeding, and avoid summer feeding that just makes crabgrass grow faster. UC IPM’s weed guide also links crabgrass to frequent light watering and mowing too short, and its general rule is to take off no more than a third of the leaf blade at a time.
Corn gluten meal: the natural pre-emergent, honestly assessed
Corn gluten meal is the one natural product with real crabgrass research behind it. Its weed-suppressing effect turned up by accident in a 1986 Iowa State University turf disease project, when creeping bentgrass seeded into plots treated with cornmeal established poorly. In Nick Christians’ Iowa State write-up, 20 lb per 1,000 sq ft cut crabgrass by 60% in 1991 and 85% in 1992, with about 50 to 60% reduction typical in the first year. It stops sprouting seeds from forming roots; it does nothing to crabgrass that has already rooted, and the nitrogen it carries can actually feed those plants.
Later evaluations have been less kind:
- UMass reports 50 to 60% control in year one and up to 90% after three straight years, but its own study found the effect mostly tracked the nitrogen supplied rather than a separate weed-killing action. UMass also calls it much more expensive than conventional pre-emergents.
- UC IPM says California lawn trials did not find satisfactory weed control.
- Washington State’s Linda Chalker-Scott, in “The Myth of Weed-Killing Gluten,” notes greenhouse results often failed to repeat in the field, and that it needs a dry spell after germination to work, so wet springs undo it.
If you try it, apply at the rate on the bag, timed close to when crabgrass starts germinating in your area (Iowa State says microbes break it down if it goes on too early). Think of it as a lawn fertilizer with some pre-emergent effect, not a dependable crabgrass preventer. And never put it where you are about to seed: Iowa State found it stopped root formation in germinating grass seedlings too.
Vinegar, clove oil and boiling water
All three are contact treatments. They damage the leaves they touch and don’t move down into the roots. UC IPM’s lawn weed guide describes contact herbicides as burning tops without killing roots and working best on young weeds. Its bermudagrass Pest Notes lists acetic acid and clove oil products as non-selective, says they may only suppress a grassy weed, and warns they can injure any desirable plant they contact. In a lawn, that means your turf.
Oregon State says vinegar for crabgrass means a 20% product, not kitchen vinegar, and may take several applications. Like any non-selective contact spray, it will burn the turf around the weed as well. Iowa State Extension says boiling water works on young annual weeds but doesn’t kill roots, often needs repeating, and damages any plant it hits, so it belongs in sidewalk cracks. Crabgrass growing in a driveway edge or patio joint is a fair target for either. Crabgrass in the middle of the lawn is not. For mixing and strength details, see our homemade weed killer guide.
Baking soda and cola
We found no university or extension research showing that baking soda or cola kills crabgrass. Baking soda is sodium bicarbonate, a salt. In one Ask Extension case, baking soda that fell onto an Iowa bluegrass and fescue lawn left large yellow, dying patches within about a day. The homeowner had read that some people use it on crabgrass; the expert said the sodium bicarbonate had likely killed the grass and advised heavy watering to leach the sodium before replanting. Skip both.
| Natural method | What it does | Use it for |
|---|---|---|
| Mowing at about 3 in | Shades soil so seed doesn’t sprout | Every lawn, every season (cool-season heights) |
| Hand-pulling | Removes the whole plant before it seeds | Scattered young plants, late spring to midsummer |
| Late-summer overseeding | Fills gaps before next spring’s germination | Thin cool-season lawns |
| Corn gluten meal | Partial pre-emergent effect plus nitrogen | Optional; results vary, not before seeding |
| Vinegar, clove oil, boiling water | Burns leaves on contact, any plant | Cracks and edges, not turf |
| Clear plastic (solarizing) | Heats and kills plants and seed underneath | Patches you plan to replant anyway |
| Baking soda, cola | No research support; baking soda can kill turf | Nothing |
Solarizing or smothering a patch
If one section of lawn is more crabgrass than grass and you plan to reseed it anyway, covering it kills everything underneath, lawn grass included. UC IPM’s solarization guidance, written for bermudagrass, calls for clear plastic kept intact for 4 to 6 weeks during the period of strongest sun (roughly June through August in California’s Central Valley), and says it can kill seed as well as plants. Treat this as renovation, not as a way to clean up a mostly healthy lawn.
Overseed in late summer to close the gaps
Every bare or thin spot is an opening for next spring’s crabgrass seed. For cool-season lawns, late summer into early fall is the time to fill them. UMass explains why: seedings made then face far less summer weed pressure, and any weeds that sprout seldom get big enough to matter before cold weather kills them. Spring seedings, by contrast, run straight into crabgrass germination. In Oklahoma, Oklahoma State puts the ideal cool-season seeding window at late September and October; farther north it comes earlier. Our guide to when to plant grass seed lists regional windows, and how to plant grass seed covers the steps.
Two cautions keep the plan natural and working. Don’t put corn gluten meal on freshly seeded areas. And while new grass is coming in, Oklahoma State says hand-pulling is the way to handle weeds in small areas, with herbicides avoided for at least the first three to four weeks after planting.
Stop pulling once crabgrass has gone to seed.
By late summer, mature crabgrass carries ripe seedheads, and yanking a big plant out shakes that seed across the soil you just cleared. If you must remove it, slip a bag over the plant first and bag everything. Otherwise, just keep mowing and let frost finish it off. Penn State says late-summer and early-fall seed is what produces next year’s plants, so spend your effort on prevention: mow high, overseed thin areas in late summer, and plan your spring approach.
If you would rather hand the crabgrass problem to someone else, our lawn weed control page connects you with a lawn care company serving your area.
If natural methods aren’t enough and you decide to use an herbicide after all, our crabgrass killer roundup covers the post-emergent options, and how to prevent crabgrass covers spring pre-emergent timing. For lower-input lawn care overall, see our organic lawn care guide.
Natural crabgrass control FAQs
Does baking soda kill crabgrass?
We found no research showing it does. Baking soda is a sodium salt, and in one Ask Extension case, baking soda spilled on a bluegrass and fescue lawn killed patches of grass, and the expert advised flushing the soil with water before replanting.
Does cola kill crabgrass?
We found no university or extension research supporting it. Mowing high and pulling young plants are far more reliable.
Does vinegar kill crabgrass in a lawn?
It burns the leaves, but it is non-selective, so it burns the grass around the crabgrass too. Oregon State says it takes a 20% product and possibly several applications. Use it on cracks and edges, not in turf.
Is it worth pulling crabgrass by hand?
Yes, for scattered young plants before they seed. Pull when the soil is moist, get the whole root clump and bag the plants. Late in summer, once seedheads are ripe, mowing and waiting for frost is usually better.
Does corn gluten meal really prevent crabgrass?
Partly, and inconsistently. Iowa State reported 50 to 60% first-year reduction and UMass cites studies reaching up to 90% after three years, but California trials found it unsatisfactory and UMass tied much of its effect to its nitrogen.
Will crabgrass come back next year?
The plants won’t; frost kills them. Their seed will, so how much returns depends on how much seed was dropped and how thick and tall your lawn is next spring. See when crabgrass dies for the full life cycle.
Related guides
Sources: Penn State Extension: Smooth and Large Crabgrass · UMass Extension: Biology and Management of Crabgrass · Purdue Extension AY-10: Crabgrass · University of Minnesota Extension: Crabgrass · Oregon State Extension: How do I get rid of crabgrass? · UC IPM Pest Notes: Weed Management in Lawns · UC IPM Pest Notes: Bermudagrass · Iowa State (Christians): Corn gluten meal · WSU (Chalker-Scott): The Myth of Weed-Killing Gluten · Iowa State Extension: Boiling water for weeds · Ask Extension: Baking soda damaged my lawn · Oklahoma State HLA-6419: Establishing a Lawn in Oklahoma · Colorado State PlantTalk: Crabgrass
