ST. LOUIS – It has been a hot July so far and we need some rain. Lawns and landscapes are struggling. Weeds are growing strong and Japanese beetles are starting to destroy some of our favorite plants.
“This kind of weather is terrible for grass. It’s very stressful. And the humidity sets up a lot of disease potential. So, it’s not a good thing for our landscape plants,” said horticulturalist Jeff Travers.
Water your grass. Either irrigate every other morning or move a sprinkler around your yard and water each zone for 45 minutes. Don’t forget about your landscape plants. They need to be soaked two to three times a week.
Grass doesn’t grow much in this heat. Skipping a mowing is a good thing for your grass when temperatures climb into 90s. But weeds are able to tolerate heat, which is a problem.
“Crabgrass, spurge, (nutgrass), those are three weeds that can actually continue to grow at temperatures above 95 to 100 degrees,” Travers said. “But the weeds, they don’t care about the heat and that’s why they’re such a pain in the grass this time of year.”
Spurge is usually found in mulched landscape beds. It’s easy to pull. Then apply preen to control it through the fall. Crabgrass can only be pulled at this point. And nuts grass should be sprayed with halosulfuron in the cool of the morning.
Grubs and beetles can also wreak havoc on your yard this time of year.
“The beetles, the masked chafers, the June bugs, and the Japanese beetles are swarming. They’ve been doing so for about a week or two. The Japanese beetles are a little late this year compared to normal seasons,” said Travers.
Shine a flashlight about two feet off the ground at night. If you see dozens of beetles swarming, you’re going to have a grub problem soon. Grubs will eat your grass roots so it’s important to get a grub product down.
As for beetles, the Japanese Beetle is the worst for our gardens.
“But a Japanese beetle, they’ll be all over hibiscus plants, garden plants, spices, herbs and you know, vegetables. Heavy feeding on the leaves with the Japanese beetles, you’re going to have to do something about it because they can actually wipe out a garden in a couple of days,” said Travers.
You can use an insecticide but be very careful to only get the leaves. If you spray the flowers you will kill pollinators. A safer alternative is an insecticidal soap, which is an organic product.