What is Crabgrass and How Do I Control It?

Crabgrass is just as icky as it sounds. It’s an annual grassy weed that spreads thousands of seeds during its lifespan. 

What is Crabgrass and How Do I Control It?

Keep your lawn thick and healthy. 

A lush, dense lawn is one of the best defenses against grassy weeds like crabgrass. Healthy turfgrass with little to no bare spots, supported by regular feedings and deep waterings, naturally wards off a wide range of these pesky plants.

Digitaria violascens plant3 by Harry Rose is licensed under CC BY 2.0 US

Crabgrass. It's just as icky as it sounds, not to mention stubborn, invasive, and aggressive. Worse, it spends its one-season lifetime spreading thousands of grassy weed seeds—seeds that lie in wait, ready to emerge the following spring to drive lawn lovers like yourself crazy all over again. An annual grassy weed that derives its name from how it looks, crabgrass has a low-growing center clump with radiating "legs" or stems. It's easy to spot and is found pretty much anywhere turfgrass is found—in the North, in the South, in every type of grass. Crabgrass thrives in the stressed-out areas of your lawn, namely the places with dried-out, thin, or sun-scorched turf. Left on its own, crabgrass can overrun your yard. Here's how to keep that from happening.

Get ‘em when they're young.

It's much easier to manage baby crabgrass seedlings than it is to get rid of uber-tough mature plants. As soon as crabgrass begins to sprout in the lawn early spring, apply Roundup® For Lawns, following all directions. It will zap those pesky little weeds down to the roots and is rainproof in just 3 hours.

Mow at the right height. 

For most turfgrasses, set your mower at a 3-inch cut. For Southern zoysiagrass lawns, set your mower at 1 to 2 inches high. Mowing a little higher lets grass do the work of shading and cooling the soil—and since crabgrass hates cool conditions, it will be less likely to germinate.

Tackle any of the spots you missed. 

Even the most eagle-eyed weed spotters can sometimes overlook a spot or two of crabgrass, until you stumble across them one summer day and they've already grown into ugly, mature clumps. If this happens on your Northern lawn, get to the root of the problem—literally—by applying Roundup® For Lawns Crabgrass Destroyer1 as directed. Developed specifically to fight tough-to-kill, late-stage crabgrass, it wins the day by robbing crabgrass of its ability to absorb much-needed sunlight, bringing it to a very timely end. (Please note that this product is for cool-season grasses only.)

Protect your landscape. 

Crabgrass isn't just a lawn invader—it will try to take over your landscaping too, if you let it. So don't! Apply Roundup® Landscape Weed Preventer in the spring to create a weed barrier that will protect against crabgrass and other listed weeds for up to 6 months. If crabgrass already has a toe-hold in your landscape, tackle it instead with Roundup® Ready-to-Use Weed & Grass Killer III with Sure Shot® Wand. The wand lets you target crabgrass and other weeds with impressive precision. The product is absorbed by the leaves and, since it breaks down without moving in or on the soil, it won't harm the surrounding plants you actually want to keep. With both of these products, of course, be sure to read and follow all directions.

Sure, tackling crabgrass can be a challenge—but there's no need to feel hopeless or helpless. Armed with these tips, you'll be able to stop even the toughest crabgrass!