So far we have focused on the different types of broadleaf weeds common in Colorado lawns and landscapes.  Now we would like to familiarize you with what we call “grassy weeds”.  What is a grassy weed?  Simply put it is any kind of grass foreign to your lawn or as we like to call them the “undesirables”, and there are many. 

Most people are familiar with the name of the most infamous type of grassy weed, crabgrass.  However, many people confuse crabgrass with quackgrass, hard fescue or any other grass that has taken up residence in their lawn.  We want to take some time in this post to allow you to see the difference and talk about controlling these types of nuisance grasses. 

This picture is of quackgrass, also a perennial, so it will come back yearly. The only chemical control for this type of grass is a non-selective herbicide like Roundup. Usually two days after mowing, the weed will be two to three inches taller than the turf. During this stage using a nitrile exam glove under a cotton glove dipped in Roundup and carefully rubbing the taller blades of the quackgrass will give you control.
The picture above shows a clump of hard or tall fescue in a bluegrass lawn. Like bluegrass, fescue is a perennial and will often green up earlier in the spring than your bluegrass. Control methods are very limited for this type of grass. Either dig up the infected clumps or treat it with Roundup before reseeding or sodding.
Another photo of hard or tall fescue which grows in clumps.
The is a picture of maturing crabgrass infestation along the sidewalk in bluegrass turf later in June. This is very typical of crabgrass to sprout along the edges as well as thin areas. Notice the wider tipped grass that is lime green in color!

The biggest difference between crabgrass and the other two types of grassy weeds is that crabgrass is not a perennial but an annual.  In other words it germinates, sets seed, then dies, usually after the first hard frost in the fall.  A single crabgrass plant has the ability to produce 150,000 seeds, and they can remain viable in the soil for up to 3 years. It normally doesn’t germinate until very late May or early June.  So keep that in mind in April when you think that clump of something in your yard is crabgrass, it is more than likely another weedy type of grass.

Another undesirable grass is Yellow Nutsedge. This grass grows far more rapidly than Bluegrass for example. It is easily identifiable because of it’s rapid growth and yellower appearance and triangular stem structure. If you roll a blade of grass back and forth between your fingers, you will feel the triangular shape of the stem. This grass can be controlled by a specialty herbicide which will deny the leaves photosynthesis and bleach the blades. We offer this service to our lawn fertilization package customers.

The above picture was taken in a newly sodded lawn. The Yellow Nutsedge is growing more rapidly than the Bluegrass/Fescue blend and has been treated with a specialty herbicide and starting to bleach white.

Windmill grass is another undesirable grass type which is easily spread. The grass blades are course in feel and have a bluish, pale green to tan color. It is a clump grass and a perennial here in Colorado. The seeds are very distinctive as you can see in the picture below the resemble a windmill and are easily spread by the wind. This undesirable grass type is controlled by a specialty herbicide and will take more than one application.

This is a dormant clump of windmill grass.

Cheatgrass or Downy Brome grass is a winter annual that can be seen now. Because of the colder temps some of the leaves have a purple coloration. The leaves are soft and have a “downy” feel to them. Once Cheatgrass is mature the droopy seeds help with identification. This grass dies off early and spreads quickly by seed so not allowing it seed out is important for control.

Next is a helpful video showing how to identify mature Cheatgrass.

EcoTurf of Northern Colorado

1101 Automation Drive #664
Windsor, CO 80550

Servicing Northern Colorado including Fort Collins, Loveland, Greeley, Windsor, Eaton, Evans, Johnstown, Severance, Timnath.