No one wants a lawn that is beset by crabgrass. What is this plant? Why is it considered so objectionable, and when and why does it grow on a lawn? How does one get rid of it?
What Is Crabgrass?
Crabgrass is a plant that, because it is undesirable, is considered a weed in the United States. Although there are several species, they all resemble grass; the main difference is that crabgrass is rougher to the touch, and rather than consisting of single blades, it has long, multi-bladed clusters which to some resemble fingers (the Latin name of the plant family, Digitaria, means “fingerlike) and reminds others of the legs of a crab, hence the name.
What’s So Bad About Crabgrass?
Crabgrass is less comfortable to walk on without shoes, but it otherwise is not painful to the touch. It is not poisonous, and in fact, its seeds are edible (in some parts of Africa it is actually grown as a crop). Its main drawback is that it is extremely unsightly and can make a lawn into a grim spectacle come fall. This is because crabgrass is an annual plant. Ordinary grass is perennial, which means that in very hot, very dry, or very cold weather it will go dormant and turn brown but is still alive. When the weather becomes wetter and warm, yard grass comes back to life. By contrast, crabgrass thrives in hot weather but dies in the cold. Once it is dead, it is dead and will remain crunchy and brown no matter the weather. If enough crabgrass spreads across a lawn, it can drive out healthier grass (which has no more room to grow) and will turn the entire lawn into a brown eyesore.
When Will Crabgrass Grow?
Crabgrass is a durable plant. It grows in places where regular grass will not (such as bald or thin patches in a lawn) and has a very high tolerance for salt, which is why it will grow on the roadside even after an icy winter that has seen enough salt put out to kill regular grass. It will also tolerate densely packed soil, whereas turf grass will not.
Once it grows, it can grow taller and wider and crowd out regular grass, especially when that grass goes dormant in the heat of summer; that’s when crabgrass thrives. It also puts out an enormous amount of seeds in the summer before it dies in the fall, waiting for spring rains to start the growing cycle again in a different part of the lawn.
How to Get Rid of Crabgrass?
Once crabgrass has invaded a lawn, there are few options for getting rid of it.
If there are only a few patches, these can be dealt with using certain kinds of herbicides. Alternatively, the plants can be pulled up by hand, though this is best done early, before it has released seeds.
Beyond that, the best thing may be to wait until the wintertime. Lawn grass will grow through dead crabgrass the next spring, provided a lawn is seeded and the crabgrass is broken up using a rake or a grass stitcher during the wintertime.
Prevention
A better option for dealing with crabgrass is making sure it never comes up in the first place.
Although crabgrass grows so quickly that it can outcompete turf grass, this is only under certain conditions. Most notably, crabgrass needs quite a bit of water early on for its seeds. A lawn that is watered just enough to nourish the existing turf grass will keep those crabgrass seeds from growing.
Furthermore, existing grass has the advantage over crabgrass seeds in that sunlight cannot reach beneath its cover. However, lawns that are too closely cut will allow those seeds to germinate. The best way to prevent crabgrass is regular mowing at a higher setting in spring and summer.
Finally, the best way to prevent crabgrass is to be alert for the lawn conditions under which it might thrive. If there are any weak or bald patches, these should be seeded to ensure that turf grass grows there, and any compacted soil should be broken and loosened to deny crabgrass a foothold.
Dealing with Crabgrass
In the Tri-Cities area, Promier Landscapes can help with creating or maintaining a beautiful, lush, crabgrass-free lawn, and has been providing lawn maintenance and landscaping services for 20 years. For more information, call (423) 872-2988, or fill out the form on the website.