Late summer in the Midwest means crabgrass. Some summers are worse than others for this hot-weather nuisance grass. And this summer has proven to be a good one for crabgrass, meaning a bad one for lawns. Fortunately, an organic approach to control crabgrass can work over time to reduce its presence.
In order to control crabgrass, it’s important to understand what’s going on in your lawn this time of year as well as how crabgrass grows.
About Summer Lawns:
- Summer brings quite a bit of stress to lawn grasses.
- Heat and drought, such as the conditions we’re currently experiencing, damage the lawn.
- Add to that the fact that we aren’t as forgiving of the lawn’s appearance in the summer as we are in the winter.
- We want our lawns lush and green in the summertime for outdoor activities.
- We try to fight nature by continuing to fertilize, water, and coax new growth out of our lawns no matter what the weather.
- Cool-season grasses, such as the fescue, bluegrass, and rye found in Midwest lawns, grow best when temperatures are in the 60-degree range.
- Once temperatures get into the 80s and above, lawns will begin to struggle a little.
- Growth slows, color fades, and lawns will show signs of wear and tear as they are less able to recover from stress and traffic.
- Some cool-season lawns will even go dormant in the summer, looking brown and brittle until early fall when they bounce back.
Now here are some facts about crabgrass:
- Crabgrass is an annual weed.
- It grows from seed each year.
- Crabgrass loves hot, dry weather and thrives in temperatures of 80 degrees and hotter.
- Furthermore, crabgrass picks up steam just as lawn grasses are slowing down.
- Crabgrass will take advantages of bare patches in the turf.
- It loves hot areas by paved driveways and walkways.
Luckily, you don’t have to resort to using harmful, toxic herbicides to control crabgrass. These unsafe chemicals may kill the crabgrass on the spot, but don’t actually control crabgrass in the future.
Here are some tips on how to control crabgrass, organically and sustainably:
- Pull it: Pull out the crabgrass by hand or spot treat with an organic herbicide. And cover bare areas immediately with sod or seed.
- Mow high: Mow no lower than 3″ from spring on. Crabgrass seed needs light to germinate. Taller grass shades the soil and keeps it cool, minimizing germination of weed seeds. Crabgrass takes off when people mow too low or scalp a patch in summer. When you open up the light canopy in the lawn, more crabgrass seeds germinate.
- Seed: Put down desirable grass seed on any bare patches as you see them. And we recommend overseeding your entire turf in fall.
- Prevent: Fertilize with corn gluten meal in the spring. Studies show that corn gluten has some pre-emergent benefits. That means it prevents seeds from germinating, so applying it at the right time of year will control crabgrass and other undesirable turf plants.
- Bag it: At Greenwise, we don’t usually like to remove clippings from the lawn. But if you have a lot of crabgrass, bag your clippings when you mow the crabgrass this time of year. Get rid of the crabgrass seeds and you will prevent them from germinating in your lawn.
- Keep calm: Don’t get too wrung out about killing crabgrass in August. It’s going to be dead at the first frost, anyhow. It’s an annual grass.
Finally, for more information on how to control crabgrass safely and sustainably, please read about Greenwise’s Organic Lawn Care Program.