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Crabgrass

With summer on its way, people everywhere are preparing for weed season.

You might see all kinds of plants invading your lawn this summer. Some are harder to spot than others; some even blend in with your grass!

Crabgrass is one of these sneaky weeds. In fact, some people are surprised to hear that it’s a “weed” at all!

Here’s everything you need to know to keep this grass impersonator from invading your lawn this year.

Crabgrass growing in a rocky garden area.

What Classifies a Plant as a “Weed?”

Firstly, the definition of a weed is…well, mostly up to you!

If you ask someone on the street, they’ll probably define a weed as an invasive plant that harms the other plants around it. But this isn’t technically the case.

A weed is actually any plant growing where it shouldn’t be. Even the prettiest, least harmful wildflower can be a weed if you don’t want it growing in your yard!

So, if you want crabgrass in your yard…it’s no longer considered a weed. But if you don’t, like many other gardeners and homeowners, it counts!


Identifying Crabgrass

Let’s talk about how to spot crabgrass camouflaging itself with the rest of your grass.

Closeup of a crabgrass plant showing the spindle, leg-like shape the plant is named for.

Appearance

If you look closely at your lawn, you might notice patches of grass where the blades are thicker, longer, and rougher than the surrounding grass.

These blades may also be a different shade of green than the rest of your lawn.

If you spot a patch like this, you’ve likely got crabgrass on your hands.

Another way to spot it? Look for a clump of grass where the blades grow spindly and spider-like.

Crabgrass is named because its blade arrangement tends to mimic a crab’s legs!

Varieties of Crabgrass

There are two common varieties of crabgrass: hairy crabgrass and smooth crabgrass.

Hairy crabgrass, predictably, can be identified in part due to the fibers on its stems.

A group of hairy crabgrass.

These fine, harmless protrusions are white and somewhat resemble cat whiskers.

Another way you can identify hairy crabgrass is by its height. Hairy crabgrass can grow up to a foot taller than smooth crabgrass. (Up to three and a half feet!)

You’ll also see the blades of hairy crabgrass looking more stem-like. The blades start thick closer to the base of the plant, but you’ll see long stems protruding further out.

Smooth crabgrass—again, predictably—is smooth to the touch, lacking the fibers of hairy crabgrass.

It also lacks the long stems that hairy crabgrass produces. Its blades are thick and smooth throughout the entire plant.

A single crabgrass plant in soil.

Where to Look

Both crabgrass varieties thrive in clay or sand-dominant soils, so if your yard consists of these, your odds of spotting this weed are high.

Crabgrass seems to prefer spots where the surrounding grass is thinner, including the perimeter of your yard.

Beyond that, crabgrass can pop up just about anywhere, so you must keep a sharp eye out!


The Impact of Crabgrass

Clusters of crabgrass plants growing along the edge of a lawn next to a sidewarlk.

Let’s go over why you want to eradicate this weed from your lawn…and why you might want to keep it!

Harmful Traits

While it is considered a weed, the truth is…crabgrass may not harm your other grass.

Some lawn experts claim that, for the most part, crabgrass can coexist peacefully with all the other plants in your yard. It doesn’t steal nutrients or consume more than its share of water.

Others state it will do exactly that, and you should do your best to eradicate it where you can.

One thing people agree on across the board? At the end of the warm season, crabgrass turns limp and brown. If you’re going for a classic interpretation of curb appeal, this creates an undesirable picture.

Beneficial Traits

One reason you might want to keep your crabgrass? If you’re a farmer who keeps livestock!

Hairy crabgrass, in particular, is known to be an unusually high-protein grass. It’s a great thing to encourage in places where your animals will be grazing.


How to Eliminate Crabgrass

Crabgrass is notoriously difficult to kill. It’s the roach of grasses. However, there are some ways to tackle an infestation.

Using a garden sprayer on weeds growing along a fence.

What NOT to Do

First, if you choose to go the weedkiller route, don’t pick just any weedkiller. Some weedkillers will cause just as much damage to the rest of your yard as they will to the weeds.

Avoid anything classified as a nonselective herbicide. As the name suggests, these weed-killing chemicals don’t stop at weeds.

Of course, this also means that many selective weedkillers won’t kill crabgrass, either—they’re designed to be gentle on grass. Even the kind you don’t want!

Second, don’t think that mowing it will solve the problem! Crabgrass keeps growing throughout the warm months, so even if you mow it down, it’s just going to come back.

Third, though selective herbicides are designed to get rid of crabgrass, they don’t work as well on mature plants.

So unless your infestation is in the early stages of growth, these might not be as effective as you hope.

What To Do

Instead, the best method for getting rid of crabgrass is to use something called a pre-emergent weedkiller.

A pre-emergent weedkiller is designed to kill the crabgrass early in the season—before the seeds even sprout!

Crabgrass growing in between garden pavers.

When the patches of crabgrass die in the fall, you’ll want to pull them up; don’t leave them where they are.

Even though the plants are dead, dead crabgrass can cause other plants not to grow around it, giving it plenty of room when it returns next season.

For the winter, leave these patches bare; you want to remember where you need to apply the pre-emergent herbicide come spring.

If this doesn’t do the trick and you start noticing seedlings in the spring, this will be the time to apply a post-emergent herbicide.

Once you’ve taken care of the seedlings, you’re all set to plant new grass to replace the crabgrass!

What You’ll Need

We recommend heading over to Amazon and snagging pre-emergent crabgrass killer. You can also order a post-emergent herbicide to have on hand, just in case!

You can also order a grass seed and lawn fertilizer combo when it’s time to reseed the bare patches on your lawn!


Wrapping Up Crabgrass

Closeup of the stems of hairy crabgrass.

Now you have everything you need to tackle the crabgrass infestation in your yard!

Keep your eyes peeled for this sneaky weed this spring and summer. To learn what other weeds you should watch out for, read our guide all about common weeds now!