Crabgrass Explained: How to Prevent and Get Rid of Crabgrass

Crabgrass (Digitaria) is a pesky and elusive annual weed. It’s not as aggressive as other lawn weeds, and its leaf blades aren’t quite as noticeable as those found on broadleaf weeds. But crabgrass still routinely appears as an infestation in bare patches of lawns. Large crabgrass (Digitaria sanguinalis), also known as hairy crabgrass, is the most widespread type of this family of grassy weeds. Smooth crabgrass (Digitaria ischaemum) is another.

Perhaps the most notable and obnoxious trait of crabgrass plants is their endless ability to shed seeds for the entirety of their life cycles, rather than just in early spring. By the time you think you’ve taken care of the issue, crabgrass seeds have shed by the hundreds of thousands into your lawn grass only to rise up again the following spring. Typical approaches to mowing or weeding can end up exacerbating your crabgrass problem, as the clippings shed weed seeds across your lawn grass. This can make what should have been a one-time headache a perennial grass problem.

Crabgrass control becomes as simple as any other form of weed control once you know how to eliminate this type of grass effectively and efficiently. Follow these steps next spring to ensure a more seamless growing season:

• Learn how to identify it. To be an effective weed killer, learn the differences between grass types and weed varieties. For instance, crabgrass shares some similarities with the fescue weed, a cool-season perennial that thrives in colder climates and lives year-round; however, crabgrass is a warm-season annual that shows up in spring and dies in cooler temperatures. Alternative approaches are called for with each type of weed. Knowing you’re dealing with crabgrass rather than another lawn pest sets you up for success.
• Learn its locale. Crabgrass craves sunlight and room to fulfill its destiny as a spreader, so seedlings most often sprout in bare spots throughout lawns or at their edges. That’s not to say crabgrass never appears anywhere else, but it’s a handy shortcut to identifying whether or not you’re dealing with this specific problem or different types of grass or weeds.
• Use the right herbicides. Once crabgrass has made an appearance in your lawn, a post-emergent herbicide will serve you well to attack the roots of weeds to kill them. It’s worth taking into consideration that post-emergent herbicides can pose a danger to other elements of your lawn, as they can be indiscriminate in killing other grass types. However, since crabgrass often grows apart from other foliage, there’s less cause for concern.
• Mow appropriately. It seems counterintuitive, but mowing close to the ground may actually make your crabgrass issue more severe. If you leave your grass higher, it creates a shadier environment and, as a result, makes it more difficult for this specific weed to take in the sunshine it needs to survive. Also, crabgrass is notoriously difficult to cut with a lawn mower given how flat it can be, and it sheds its seeds even if cut short. Save yourself some time on this front by keeping your mowing height high and addressing the problem through other means.
• Pull when possible. Pulling out crabgrass by the root is still a reliable method of handling this issue before it gets out of hand. The more time it spends in your lawn, the more seeds it will shed, continuing its seemingly endless cycle of reappearance.

Learn how you can stop crabgrass from becoming an issue with these preliminary tips:

1. 1. Reduce bare patches. Crabgrass grows best in bare spaces, so tending to your lawn regularly and ensuring few to no empty areas exist will greatly reduce any possible appearance of the weed. It won’t solve the problem on its own, but it gives you a solid head start.
2. 2. Fertilize well. It’s harder for crabgrass to grow in healthy, full landscaping than it is in barren spaces. One of the foremost keys to an abundant lawn is fertilizing often and appropriately. If your lawn is fed well with mulch, ample fertilization, and the other active ingredients it needs to thrive, it will flourish—and there will be far fewer opportunities for crabgrass to appear.
3. 3. Use herbicides proactively. To prevent crabgrass germination, it’s useful to get ahead of weed killers. Pre-emergent herbicides can stop crabgrass if you time things correctly—in other words, you want to apply these when soil temperatures are hotter in early spring and crabgrass is germinating, as well as before they can adversely affect anything else you’re newly planting in your lawn.
4. 4. Practice seasonal lawn care. The best defense against crabgrass is tending to your lawn with vigilance and care all year long. It means applying pre-emergent herbicides in spring and post-emergent ones in fall, watering often in summer, and preparing for next year’s lawn care in winter. The healthier your lawn is in all seasons, the harder it will be for crabgrass to gain a foothold.

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