How can you get rid of crabgrass in your yard? Your options include pulling the plants at their roots, applying weed killers or turning to lawn care professionals.
No matter what method you choose, you may face an ongoing battle.
Crabgrass — at first it seems like nothing but an oddly colored blade here or there, poking up among the otherwise rich green turf. Then, as soon as you let your guard down, you realize it’s a full offensive. The crabgrass has arrived to sabotage your immaculate landscaping. (OK, maybe not immaculate…)
Before the invasion takes over, there’s a lot you can do in the fight against crabgrass. After you’ve launched your counterattack — whether by hand-to-hand combat (weeding) or chemical warfare (applying weed killers) or calling in reinforcements (hiring a professional) — the crabgrass will retreat and your lawn will again rank as one of the best in the neighborhood.
What Is Crabgrass?
Crabgrass is an annual weed that favors compacted soil where the grass is in a thinned and weakened condition. During the early spring and summer, crabgrass germinates when soil temperatures are between 55 and 65 degrees about 3 inches below the surface.
With coarse, yellowish leaves, this weed is easy to spot among the green, fine leaves of turf. Crabgrass grows in bunches, like the arms of a crab, or like troops spread out across a battlefield.
The real concern is the crabgrass growth cycle. A single plant produces as many as 150,000 crabgrass seeds. And these seeds can lie dormant for as long as 30 years.
What this means: Each growing season is just one battle in the ongoing war against crabgrass.
With proper planning and preparation, it is possible to be victorious against crabgrass. While it’s unlikely you will ever totally sign a peace treaty with this weed, you can control crabgrass and come out of this fight on top.
Read on for your tactical training.
How to Get Rid of Crabgrass
Weeding (on-the-ground combat)
Pulling the individual crabgrass plants can be a helpful plan of attack. Getting crabgrass out at its root level is one of the surest ways to kill crabgrass, but it is tiring and takes time and patience.
Unfortunately, maintaining crabgrass control means regularly weeding your lawn.
When to attack: Weeding should be done in late spring, before the crabgrass plant grows large and distributes its seeds. As with all weeding, this job is easiest following a rain when the soil is moist and soft.
Corn gluten meal
This is a natural remedy that won’t harm your grass. Corn gluten meal (CGM) is a byproduct of corn and can be used to contain all broadleaf weeds, including clover and dandelions. The proteins in corn gluten meal slow seedlings’ roots, while also adding nitrogen to support turf growth.
Corn gluten meal needs to be applied liberally, and this will cost about $30 for 1,000 square feet of lawn.
A healthy lawn
Your best defense against crabgrass is as simple as a healthy lawn. The shade created by a dense turf will prevent seeds from germinating, giving you an automatic advantage in the fight. There are a few ways to encourage a healthy lawn and discourage crabgrass.
First, trim your grass to the highest recommended height. Regular mowing serves as a natural crabgrass preventer, choking many weeds. You’ll also want to water deeply but infrequently; this will kill the shallow-rooted enemy as the top of the soil will dry out in between waterings.
If you live in a colder region, fall is the best time to plant new grass seed as frost kills crabgrass seedlings. When seeding bare spots, water regularly. Apply a crabgrass preventer in the spring.
Pro tip: One common misconception is that cutting crabgrass short will kill it off quickly. This little villain can produce seeds even at just ½-inch tall, which is much shorter than any residential lawn should be mowed. Like with most weeds, it’s important to get the roots, and get them early.
Apply weed killers (chemical warfare)
A common choice for any weed issue is topical applications. You’ll find lots of options at your local home store, but not all herbicides are created equal. Here’s a bit of information to help you in your advancement on crabgrass.
It’s important to choose a selective product, as it will attack certain weeds without permanently damaging the surrounding grass. You also need a product targeting invasive grasses; crabgrass is a grass, not a broad-leaf weed.
Look for one of these active ingredients:
- Oryzalin (works especially well on warm-season grasses)
Finally, liquid and granular options work equally as well. However, liquid products require a calibrated sprayer. It’s unlikely you already have a sprayer in your toolshed, but out in that cache of tools is probably a spreader. This alone might make granular options your best route.
After application, be sure to water according to the product’s instructions.
Pre-emergent weed killer
This is the most effective and economical tool in the struggle with crabgrass. Pre-emergent herbicides interrupt the growth process, preventing complete germination.
These products shouldn’t be used on grass that hasn’t established itself. For best results, preseed in the fall, and apply these remedies in the spring, before the weeds have a chance to germinate.
Post-emergent weed killer
Once crabgrass has staked its claim to your yard, it’s time to diversify your arsenal. Post-emergent herbicides target the plant itself, killing it before it has the opportunity to produce more seeds.
Stay away from “weed and feed” varieties, which combine herbicides and fertilizers. Because crabgrass is a variety of grass, these applications will actually nourish the invaders. Look for selective, post-emergent applications specifically targeting crabgrass.
Always read product labels carefully; ensure your grass type is listed as approved. More importantly, though, is to read and follow all safety directions. These are chemicals, and while they can be helpful in achieving landscape victory, they also can be dangerous.
Hire a professional (call in reinforcements)
Sometimes the best thing to do is bring in backup. In this case, backup means lawn care professionals who can mount a strategic offensive on all fronts.
Once you’ve exhausted all of your own options and your lawn is about 60% crabgrass or other weeds, it’s time to call on the allied forces.