Planting Guidelines for Spring: Midwest

The Midwest has some of the richest soil in the country, if not the world, but that doesn't mean that gardeners have it easy. There are extremes in temperatures, freak climate occurrences, bugs and overdeveloped land.

For all of those problems, there is a reason it's still known as "America's breadbasket." Tim Kenny, director of education for the Minnesota Landscape Arboretum, believes gardening in the Midwest is a celebration of nature.

“There are cycles and hardships, but in the end comes all this wonderful food," Kenny said. "And it’s joyous.”

Midwestern Weather Ethics

Because it is America’s "breadbasket," a gardener in the Midwest should expect to have good soil, a long growing season and adequate rain. That is mostly correct. However, overdevelopment and new construction have taken away the rich topsoil, and some backyard gardeners find less than adequate soil conditions for planting.

“A lot of the top soil, especially in new home developments, is gone,” said Cat Blaney, retail buyer for Hinsdale Nurseries in Willowbrook, Illinois, just west of Chicago. “The soil in the Midwest is rich, but in a lot of places there is a lot of clay.”

Ben Sharda, executive director of the Kansas City (Missouri) Community Gardens, says the biggest problems are the unpredictable weather extremes.

"It can get real hot in the summer, or it can be a cool summer," Sharda said. He agrees that developers have scraped away too much topsoil.

"[It's left] people buying new homes with horrible clay," he said. "They really have to add organic matter to it."

Kenny says planting has to be timed around “big swings" in the climate.

"It’s kinda weird," he said. "It can be 20 below and then 95 degrees in a span of six months. There is always an unwritten contest in neighborhoods to see who has the first ripe red tomato. It’s a race because you wait so long for the winter to go away and then it quickly warms up and you have a wonderful growing season with an explosion of flowers and vegetables."

It's also a race because that season can come to a screeching halt with a freak early hard frost, says Kenny.

"Or you have a freak golf-ball size hailstorm in June -- or a drought or a tornado or a flood," he said. "You get these climate changes that wreck havoc, but it’s more in a localized area rather than across the region. Then you just come back the next year and start over.”

Soil Boosts

Backyard gardeners in the Midwest should never take their soil for granted. Terri James, extension assistant for the University of Nebraska-Lincoln, says the soil must be properly prepped to produce.

“The soil in the east and west of Nebraska is totally different,” she said. “No matter where you live, test the soil and put in the right fertilizers, compost and organic matter.”

She recommends adding 1 pound of an all-purpose (nitrogen, phosphorus and potassium) fertilizer per 100 square feet. Spread the fertilizer over the garden and rake it into the top 4 inches of soil before planting each crop. More nitrogen may need to be added midway through the growing season, especially for leafy crops, greens and root crops.

A little lime can fix soil with too much acid (a slightly acidic soil is ideal for growing vegetables). If the soil is too alkaline, add sulfur.

“If you want to have a good garden, you have to do the prep work, and part of that means maintaining the soil,” said Cat Blaney, a retail buyer for Hinsdale Nurseries in Willowbrook, Illinois.

Hardiness Guide

To help gardeners, the USDA in 2012 issued updated hardiness planting guidelines that indicate the average minimum winter temperature. In the Midwest, the warmest zone is 7a in southern Illinois (0 to 5 F). The coldest is in the upper regions of Minnesota with a 3a, indicating the average annual minimum winter temperature is between -40 and -35 F.

The weather in the middle part of the country can also deceive gardeners into thinking it's safe to plant outside. According to a release from the Minnesota Landscape Arboretum, this happens often in early May, and those planters are usually disappointed because a frost can still wipe out certain plants. According to the Arboretum website, petunias, coleus, begonias and other warm-weather plants should not be planted until after May 20. It is safe to plant some more tolerate items, such as snapdragons, broccoli and cauliflower, in early May.

The holidays serve as a planting guideline. Shrub rose plants can go in the ground after Mother's Day. Tomatoes, peppers and melons can be planted as part of the Memorial Day celebration.

The Illinois County Extension Office categorizes plants as hardy, half-hardy, tender and very tender and uses this classification to determine the earliest safe planting date.

According to the extension office, hardy vegetables such as asparagus, garlic, onions, turnips and spinach can be planted as soon as the ground can be prepared. Half-hardy vegetables, such as radishes, cauliflowers and chard, can be planted as early as two to three weeks before the average date of the last spring freeze.

Tender vegetables like sweet corn and snap beans should be planted about one week later, while very tender crops, such as eggplant, cucumbers and watermelon, go two to three weeks after that -- or about a month after the hardy vegetables.

Bugs

Once the plants are safely in the ground, a Midwest gardener still cannot rest. It's also fertile ground for hungry insects, and plenty of them.

“Well, we get a lot of bugs,” said Cynthia Druckenbrod, director of horticulture for the Cleveland Botanical Garden in Ohio. “You’ll see Japanese beetles and aphids, tomato fruit worms and pickleworms.”

Cabbage caterpillars, cowpea curculios, stink bugs and thrips are also among the throngs of potential unwelcome guests at Midwestern gardens. Kenny performs a constant vigil to keep his plants pest free.

“We go out daily into the garden and just pick the bugs off the leaves, find their eggs and squeeze them and put them in water jars,” Kenny said.

“The winters do kill a lot of the insects, but they tend to come back later in the season," he said.