What Is Crabgrass? How to Kill It FOREVER?

what does crabgrass look like

You have seen crabgrass. Even the hard asphalt of the street cannot stop them. They simply grow aggressively and take over everything, including your lawn. Crab grass is not just unattractive; this weed is an actual threat to your lawn and its health!

Buy now that you are here, the definite answer for “how to get rid of crabgrass” is only a few minutes away from you. We are going to cover your best options to wipe them out. We will also cover crab grass’s varieties, life cycle, what causes them, why are they considered bad, and how to prevent them in the future (You will find them useful in case you are more curious about this tough species!)


What Is Crabgrass?

Crabgrass’s scientific name is Digitaria, a genus from the grass family. Also known as the finger grass (Digitus means ‘finger in Latin), this annual or perennial weed (depending on its type) comes from tropical regions with warm temperate. However, this does not prevent these lawn pests from growing in subtropical regions with cooler temperate as well as hot and dry conditions.

Crab grass grows in bare spots on your lawn. And when dying in the fall, it produces thousands of seeds (from 80,000 to 150,000, to be exact) that germinate when the spring comes. So it is important to kill the, quickly before admitting defeat and Googling “my entire lawn is crabgrass!”

Crabgrass Identification: What Does Crabgrass Look Like?

This weed has a low-growing habit with stems radiating from the grass clump’s center. The stems resemble crab legs and light green when they are young. As the stems age, their color turns into a dark and dull green.

Another thing that can help you in crabgrass identification is its leaves that are broader than grass blades. Apart from the thousand seeds that were mentioned, this irritating clump of grass also produces long flower clusters.

The most important crab grass varieties include:

  • Hairy crabgrass (Digitaria sanguinalis) that has small hairs all over its leaves and stems (you just need to inspect it closely;
  • And small or smooth crabgrass (Digitaria ischaemum) that features relatively hairless leaves and stems. It only features a few hairs at its auricles, which are small projections on the leaves bases’ interior.

Crabgrass Life Cycle

Knowing crabgrass life cycle helps you distinguish mature grass from a young one, which later benefits you in eradicating the weed. This is because the best way to get rid of crabgrass is to keep it from growing in the first place. Killing mature finger grass is not impossible of course, it simply may be more challenging.

This weed emerges in early summer and since it handles drought without problem, thrives in hot weather. They are still green in August, and nothing less than the fall frost can kill its stems. Producing seeds at end of the growing season concludes the crabgrass life cycle.
And if these seeds germinate, you are going to look for methods how to get rid of crabgrass in your lawn in the following year.


identification crabgrass


What Causes Crabgrass?

As you can guess by now, what causes this weed is that the last year’s plants were successful in producing seed. Although the first frost killed them, the seeds remain dormant through the winter and begin to grow when the ground temperature warms up.

These seeds love sandy and compacted soil where the grass is weak and thin. Sunlight directly hits the soil where your lawn is bare and provides the perfect spot for crab grass germination and growth. And since they grow close to the ground, they scape lawnmowers easily and spread quickly.
In addition to lawns, this grass invades other landscapes such as golf courses, athletic fields, gardens, orchards, and waste places.

Why Is Crabgrass Bad?

Why is crabgrass bad you ask? Although they prevent your lawn from receiving necessary nutrients, it is not their main problem. Most of the time, they do not crowd your desired grasses out. However, they look awfully terrible at the end of summer.

So if that does not bother you, you do not have to look for ways how to get rid of crabgrass since they are not doing any harm to your lawn. It may surprise a lot of people, but crab grass actually has several benefits.

Crab Grass Benefits

Grazing animals love this weed. So they eat more of it and gain more weight than when grazing on millet and any other summer grasses and grains.
While a horrible weed, it is also one of the world’s fastest-growing cereals, producing nutritious and edible seeds. But that does not make husking the small grains any easier. The seeds are also ground up and used as flour in various recipes, made into porridge, or fermented to make beer.



How to Get Rid of Crabgrass in Your Lawn?

Finger grass will die on its own in the fall. But you do not want to give them a chance to disperse any seeds. The best way to get rid of crabgrass in your lawn is to prevent their germination. So time your prevention efforts, so you do not have to deal with this weed for another summer.

One of the best prevention efforts is simply pulling the clumps out by hand or using a garden weeder tool. This tool features a claw or plunger that you can drive deep into the ground and under crab grass roots, remove completely. Place the clumps in a trash bag and seal tight so the seeds cannot spread and sprout. Although this process is time-consuming, it is very effective in controlling finger grass.

You can also use a specialized post-emergent herbicide for crab grass. As some of the lawn weed herbicides can kill your regular grass and other common weeds. Herbicides for this weed are typically in liquid form and help in spot treatment (they do not have broadcast applications).

Note: If you already have a crabgrass infestation, you will probably need chemical treatment to get rid of crabgrass.

A homemade crabgrass killer can help too. Will vinegar kill crabgrass? That is a common question. Vinegar is acidic and burns the weeds, killing them within a short time. However, instead of only using vinegar, it is better to mix one part of baking soda with two parts vinegar and then spray the solution on crabgrass. Repeat until the weeds are removed permanently. This homemade crabgrass killer helps in dealing with other weeds too.


What to Do After Killing Finger Grass

After controlling the problem, the best way to prevent this weed includes taking care of your lawn, feeding it regularly, and watering it deeply. A thick and vibrant lawn gives finger grass little place to thrive.

Another good idea is adjusting the mowing height. Use taller grass blades to provide shade for the soil, helping to prevent crabgrass seeds’ germination.

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