Recently I had a client express frustration about his inability to kill the crabgrass weeds in his lawn.
It turns out that what he had was tall fescue rather than crabgrass. Tall fescue is a spreading cool season grass that often appears in lawns. It has a courser texture than bluegrass, and will sometimes “green up” in the spring earlier than the rest of the lawn.
How to Remove Tall Fescue
Crabgrass (left) has smooth leaves that often have small hairs. Fescue (right) has ridges on the leaves.
So here’s the thing about trying to remove it: Selective weed killers that target weeds such as crabgrass will not kill tall fescue.
The only way to remove the tall fescue is to treat it with a non-selective herbicide such as Roundup. This type of weed killer will also kill the lawn that is directly around it. Which means you will need to spot-seed that area, or if you have a lot of fescue you may need to remove the entire lawn and start over with seed or sod.
Should You Remove it at All?
In my lawn, I have clumps of tall fescue but I don’t like to use many chemicals on my lawn. I just leave the clumps in place- they are hardly noticeable once the lawn greens up.
Tall fescue emerging in a bluegrass lawn that is still dormant in early spring.
Fescues are actually pretty highly recommended as lawn grasses- according to the Colorado State University Extension Office a fescue lawn can require up to 50% less water than a bluegrass lawn. In fact, one of the popular sod blends we often specify for the front range is a “90/10 Fescue Bluegrass” blend. That is, 90% fescue and 10% bluegrass.
So before deciding to use a bunch of chemicals on the fescue in your lawn, or doing a major lawn renovation – consider leaving it in place. The fescue can be hardly visible at all from a distance, and may end up saving you money in the long term on watering.
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