Crabgrass spreads quickly and can crowd out your grass and take its nutrients.
The Spruce / Adrienne Legault
What Is Crabgrass?
Crabgrass eludes the mower blade since it hugs the ground.
The Spruce / Adrienne Legault
Even their stalks, which bear flowers and seeds, are tough and do not mind being walked on.
What Does Crabgrass Look Like?
Crabgrass looks like a coarse, light green clump of grass.
The Spruce / Adrienne Legault
Its sprawling stems resemble crab legs.
Tall fescue grass is usually darker green, thicker, and grows faster.
Crabgrass grows in many types of turf grasses.
The Spruce / Adrienne Legault
Life Cycle
Crabgrass germinates and lives for one season.
It spreads its seeds and returns the following year.
When the daily average soil temperature reaches 73F, most crabgrass seeds should have germinated.
The Spruce / Adrienne Legault
In shadier spots, it will take longer.
It will sprout faster in areas near concrete and rock since those materials conduct heat.
In the beginning stage, the crabgrass seedlings resemble miniature corn stalks.
Orest Lyzhechka / Getty Images
Then, the leaves start to branch out.
Crabgrass becomes more problematic in the summer because these weeds thrive in hot, dry weather.
That said, they are similar because both are annual grasses peaking in summer.
NY State IPM Program at Cornell University / flickr / CC BY 2.0
They thrive in nutritiously rich, sandy, or clay soils.
Hairy Crabgrass
Orest Lyzhechka / Getty Images
Hairy crabgrass is also called long crabgrass.
Their leaf blades grow about the same length, up to 6 inches long.
It is more coarse and has broader blades than smooth crabgrass.
A leaf of hairy crabgrass can be up to 1/2-inch wide, while smooth crabgrass is about 1/4-inch wide.
Its leaf blades taper to a point.
The plant’s stems bend at its nodes and sometimes turn red.
If you stop the seeds from germinating, you’ve prevented the plant from emerging.
However, sprouted crabgrass can grow more vigorously if not kept in check.
How to Prevent Crabgrass
Prevention is key.
There are various methods to do this, but twotypes of herbicideswork best: post-emergent and pre-emergent.
Those seeds will sprout next spring in your lawn unless you prevent them from germinating with a pre-emergent herbicide.
Kill crabgrass without damaging your lawn and other plants using selective post-emergent herbicides specifically formulated for crabgrass.
Using non-selective varieties of post-emergent herbicides will kill your grass because they’re formulated to killallplants.
If crabgrass has set seeds, mowing over it can distribute them over a broader area and increase spreading.
It’s best to mow regularly before it reaches the seed-bearing phase.
Pulling crabgrass is most effective when you only have small clumps of young crabgrass.
Spraying is useful when there has been widespread crabgrass growth and you need an easy, quick solution.
If you spray, use the correct bang out of post-emergent herbicide (i.e.
selective versus non-selective) for your specific situation.
Crabgrass, University of Maryland Extension
Controlling crabgrass after it emerges, Michigan State University Extension
