Listen MPR News speaks with Julie Weisenhorn, director of the Master Gardener program at the University of Minnesota
Following an unseasonably warm spring, sprouts and buds are already appearing in some parts of Minnesota.
Julie Weisenhorn, master gardener at the University of Minnesota, spoke to Tom Crann of All Things Considered on Wednesday about how best to prepare your garden this season.
An edited transcript of that discussion is below.
Tom Crann: Is there really any science to the right time to plant or does it depend on what the weather is like in a given year?
Weisenhorn: Our frost-free date in Minnesota, at least in Zone 4, is about the third week of May [and] as we go north, about two weeks later. As a rule of thumb, we want to wait until then, but we could certainly be planting cold crops such as kale and lettuces and radishes now. It's really about the soil temperatures. According to what I've seen and read, it looks like the temperatures are certainly climbing pretty quickly for us.
Crann: Might this early spring and an early warmth possibly make for a longer growing season?
Weisenhorn: It could, but this is Minnesota. And we've had late frosts before that have nipped the buds or nipped flower blossoms. It's always important to remember that we could have a frost, we've had snow as late as the third week of May before. I wouldn't be planting tomatoes and peppers yet unless you're starting the seeds indoors.
Crann: Is there any more of a risk of pests, disease or bugs because of this early spring?
Weisenhorn: Yes. Our cold temperatures typically will kill off some of the diseases and insects that thrive in these warmer weathers. But we just haven't had those temperatures this winter. They've been burrowed down in the mulch and burrowed down in the debris under the plants, and who knows, we could have a bumper crop of Japanese beetles again...It looks like they've got a head start on the season.
Crann: I imagine weeds will have a head start on the season as well. And it may be a longer growing season for them too?
Weisenhorn: That's correct. You want to practice some good weed control. And listeners can actually go on the extension garden website at the University of Minnesota website, and that will help them move around with information about drought, information about weed control and insect and pest control.
Crann: What will you be doing in your garden this weekend?
Weisenhorn: I'll probably be cleaning up my garden. I'll be cutting down my ornamental grasses because there is going to be some greenery growing. I'll be cleaning up a lot of debris, sanitation. Cleaning up that dead plant material is really important to helping to deter diseases and pests.
Then [I'll be] clearing off any type of mulch or debris away from anything that's green that's popping through, and just moving it to the side and leaving it there in case I need to just quickly put it on during an evening of frost.
Interview transcribed by Jon Collins, MPR reporter.