WASHINGTON – The first heat wave of the season was pretty brutal. And it won’t be the last, so let’s review hot weather turfgrass rules.
Follow these tips to help summer-stressed, cool-season lawns like fescue, rye and bluegrass survive heat waves.
Unless you have zoysia or Bermuda grass, do not cut your lawn during a dry heat wave – leave it alone until the weather breaks. Never cut it lower than 3 inches and always try and cut during mild weather.
Again, unless it’s zoysia or Bermuda, do not feed your lawn between now and September. Despite what that idiot with the terrible Scottish accent tells you during the ball game, your cool-season lawn is not hungry in the summer, and if you heed his potentially illegal advice to “Feed it, Feed it,” it will turn brown and die.
When you water any type of grass, water deeply and infrequently – a deep soaking of two hours or more once or twice a week is ideal. Short, frequent waterings lead to shallow roots and that leads to grass that dies during the first round of water restrictions. And do not water if we have received an inch or more of rain within the past seven days.
If you do have Bermuda or zoysia, you should feed it lightly over the summer and you can cut it lower. Those grasses love summer.
Big trees equal bad grass
Ziggie in Alexandria writes, “Thanks to many trees, my front lawn is shaded to the point where I am limited to weeds, moss and a ground cover that’s taking over. I’d like to have more of a grassy lawn. What’s the best seed for this purpose? And what else do I need to keep in mind?”
Well Zig, the first thing you need to know is that even the most shade-tolerant grass needs four hours of sun a day. If the area gets that much, rip out the moss and plants late next month, add enough lime or hardwood ash from a woodstove or fireplace to bring the soil pH up to neutral, as that moss is a sure sign of acidic soil. Then spread an inch of compost or top soil, level it out and sow a fine fescue seed between Aug. 15 and Aug. 30. That’s the only window of time that will work in your case, and the only kind of seed that has a chance in that kind of situation.
But if the area doesn’t get four hours of sun a day, make the soil more acidic so the moss will thrive or more alkaline so the groundcover will win.
Bees in the Ground? Wasp out, they may be yellow jackets
It’s time to warn listeners that ground nesting insects that look like bees are much more likely to be yellow jackets from now through the end of summer. Unlike the gentle, native, non-stinging ground nesting bees we see in the spring, yellow jackets are highly aggressive and dangerous wasps and their nests must be destroyed.
One of the safest ways to eradicate a nest is to wait until late at night and then dump a big load of ice cubes or ice chips over the hole in the ground. I fill half of a wheelbarrow with ice trucked back from a local motel in a picnic cooler when this need arises at my place. The ice will slow them down, these wasps can’t function when cold, and physically block them from leaving the nest while you work.
Then cover the hole and a little of the area around it with a thick piece of clear plastic, 2 mil is ideal, and secure the edges tightly with bricks or stone. The trapped wasps will be smothered after a week or so of cooking in the sun.
Do not dump poison down the hole. It won’t work, thanks to the clever, water- shedding construction of these underground nests. And don’t approach the nest during the day, when the wasps are at their most alert and aggressive, you’re sure to be stung. Wait until a cool evening, when the wasps are naturally slow and dormant. And have a helper ready to spray any guards with Pam or an oil-based insecticide if necessary.
Yellow jackets in the mulch pile – no problem
Liz in Mount Vernon writes, “This is the second year that yellow jackets have made a nest in my big pile of saved fall leaves. Last year my husband killed them with gasoline. I’m tired of getting stung and of hearing my husband say I shouldn’t have these piles around. What can I do to prevent future nests, so I don’t have to hear my husband say