By: Tony Koski, Turfgrass Specialist
Guess what? You might actually be seeing crabgrass in your lawn this time of year! It was late germinating this spring (we didn't see it in Fort Collins until late May), but now it's large and in charge. This is crabgrass in late May:
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| Young crabgrass |
Now it looks like this (late July):
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Small (smooth) crabgrass (Digitaria ischaemum)
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Small (smooth) crabgrass--growing in concrete!
(That's a joke) |
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| Small (smooth) crabgrass near sidewalk |
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| Crabgrass seedhead |
Many think they have crabgrass, but they don't. Here are some other crabgrass look-alikes that are often called crabgrass, but misidentified...
This is not crabgrass; this is bromegrass (wide, coarse blade; often a "W" watermark on upper tip of leaf):
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| Bromegrass in a bluegrass lawn |
This is not crabgrass; this is annual bluegrass (characteristic apple green color; often with seedheads):
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| Annual bluegrass in a Kentucky bluegrass lawn |
And this is not crabgrass; this is tall fescue (clumps of grass with rough edges on the leaf blade):
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| Tall fescue in a bluegrass lawn |
This isn't crabgrass either; this is orchardgrass (flat "stems" and tall white ligule):
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| The ligule is located like a collar on the inside of the leaf |
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| Orchardgrass in the lawn |
And no, this isn't crabgrass either; this is yellow foxtail (characteristic red base, yellow-y color):
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Yellow foxtail, which can easily be confused with crabgrass.
The great news is that the same products that work on crabgrass
will work on foxtail. |
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| Yellow foxtail--look at that distinctive red color! |
Finally, this isn't crabgrass--this is bermudagrass (forms runners, invasive, pointy leaf tip):
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| Bermudagrass |
Crabgrass is characterized by its prostrate growth habit, especially after mowing and a light, apple green leaf color. The seedheads are digitate (finger-like) and will begin forming in earnest in August. Crabgrass is a warm season grass (and a summer annual), so it will die with the first frost.
If you want to control it now, use any herbicide product containing quinclorac (such as Ortho Weed Be Gon Max Plus Crabgrass Control, Fertilome Weed Out Plus Q or Bayer All-in-One Lawn Weed and Crabgrass Killer). Be aware it may take more than one application to completely kill this persistent weed. It's much easier to control when it's a seedling or use preemergence products in early spring.
The big point to make, with the exception of foxtail and crabgrass, is that quinclorac will
not work to selectively remove tall fescue, bermudagrass, bromegrass or annual blugrass from your lawn. So identification of grasses that LOOK like crabgrass is essential before you start spraying herbicides willy-nilly.