Ask Dave Epstein: Are we in a heat wave?

Meteorologist Dave Epstein is our go-to person for pressing weather questions on everything from winter blizzards to summer droughts. He’s also a horticulturist, meaning he’s an expert in anything that grows leaves and flowers. GBH's Morning Edition asked our audience for weather and gardening questions, and Epstein graciously answered them on the air. This transcript has been edited for clarity.

Have a gardening or weather question for meteorologist Dave Epstein? Tweet him @GrowingWisdom, email us at thewakeup@wgbh.org, or text 617-300-2008.

Are we in a heat wave?

While people often use the term colloquially to talk about hot days, meteorologists don’t consider it a heat wave until an area has had recorded temperatures hit 90 for three days in a row.

“If we reach 90 today, which is a really good bet, that would be day one,” Epstein said. “Tomorrow might be day two. And then we've got to hit 90 Saturday for day three. So it's only going to be a three-day heat wave, which is a minimal heat wave.”

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Because it’s going to be hot, it’s a good idea to stay out of the sun, wear sunscreen and drink plenty of water.

“I think trying to keep all this in perspective,” Epstein said. “If you're outside, then you want to be sure you're taking care of yourself. Otherwise, this is not an unprecedented heat wave or anything like we've seen around the world this summer.”

After all the recent rain, we have a lot of mushrooms in the yard. Are they edible?

Wild mushrooms are a delightful surprise. But never, ever, ever eat a mushroom found in the yard or in the wild without being absolutely sure of what kind of mushroom it is, Epstein said.

Since the listener who sent the question did not add a photo or a description of the mushrooms, Epstein could not give a definitive answer.

“There are a lot of edible mushrooms out there this year,” Epstein said. “But, and this is the huge caveat, you can kill yourself if eat the wrong one, or get very sick.”

To be sure, there are some delicious edible mushrooms that may come up: Chanterelles, for instance, or hen of the woods mushrooms. There are also dangerous look-alikes to avoid: Toxic jack-o-lantern mushrooms and false chanterelles, which can cause severe stomach upsets; or highly toxic death cap mushrooms, which can look a bit like edible puffballs when they first pop up.

“You've got to go with somebody that really knows what they're doing,” Epstein said. “Do not do it on your own based on the Internet.”

I have extremely sandy soil in Dover and it's difficult to grow anything including grass. What can I do? — Christopher

Amending the sand with another kind of soil may be necessary, Epstein said. But there are options: Thyme may do well, as would ajuga, sometimes called bugleweed or ground pine.

“I planted the ajuga at that spot between your yard and the street, there's that little strip and that's often very sandy and gets sand from the plows and all that,” Epstein said. “And it does well. It's a nice groundcover and it actually gets a little flower.”

I have a large and growing patch of ground ivy taking over my lawn. What's the best way to prevent it from taking over?

Ground ivy is hard to get rid of, Epstein said.

“It's a very difficult plant, I have it in the in the yard as well,” Epstein said.

His treatment was more preventative: Because ivy typically comes in early in the growing season, he’ll go into his garden in the early spring and dig up its roots.

“It's like almost like a thread,” he said. “Once you get one piece of it, it's pretty easy to pull out.”

Since it’s already taken over this year: There are some nonorganic treatments, which Epstein said he tries to avoid where he can.

“Keeping the lawn really thick will help, but otherwise you're going to have to treat it with a chemical, which, as you know, I'm not a big fan of,” he said.

Dave, do you practice no-dig? — John in Rockport

The goal of no-dig or no-till gardening is to keep disturbances of the local ecosystem to a minimum, Epstein said. Instead of using a big shovel (or, in industrial farms, heavy machinery) to overturn the soil, no-till or no-dig gardening involves handling the top layer of soil more gently.

“I try to do just pull the stuff out and gently, with my hands, kind of work in some soil amendments and then plant from there,” Epstein said. “I'm not putting a big shovel down and turning the soil over. You really disturb that little ecosystem that's developed.”