Gardening experts offer summer tips

Flowers and bee
A bee flies from plant to plant while feeding on a flowering Anigozanthus, also known as Kangaroo Paws, at a nursery in San Gabriel, California on March 25, 2013.
FREDERIC J. BROWN/AFP/Getty Images

You've braved frigid temperatures under cover of darkness to tie burlap sacks around delicate shoots.

You've lugged pots inside and dragged them out and watered and drained and mulched and pruned.

You've slogged through the Muddy Season, only to hit the stark wall of humid that showed up last week.

You've waited and watched and scanned the Updraft and held your breath to see what among your favorites might survive — and what just wouldn't make it this year.

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You've got a few questions, whether you've been at it for years or you've just poured dirt in your first cluster of pots. Gardening experts Mary Meyer, a professor of horticulture at the University of Minnesota, and Michelle Mero Riedel, a master gardener with the University of Minnesota's extension and a professional photographer, joined The Daily Circuit to field questions, offer suggestions and share a few insights into where we ought to go from here.

Don't let the rainy season deceive you: Water those plants!
"We did have a lot of rain... [and] things are starting to turn around," Mary says. "It doesn't take long, though, till plants need water again, especially in our vegetable gardens."

And depending on the type of soil you've planted in, particularly if it's sandy or silty, you won't want to wait too long after the rains to water again.

Choose native plants for long-term survival
Minnesota's volatile weather (think: last year's drought and record-setting winter, June's storms and this week's soaring temperatures) has brought with it some volatility of its own in Minnesotans' gardens this summer. Callers shared stories of perennials lost, trees killed and fruit stunted.

So how can you design a garden that will thrive across the swath of weather we've been experiencing lately?

Go agile, Michelle says: "There are a lot of plants that can handle a lot of rain and also drought." Look for ones that can handle different soil types, as well as different weather.

Sun-loving plants, she says, will eventually acclimate to the changing conditions.

But your best bet, in a quest for long-term garden survival? Pick plants native to Minnesota.

Those are the ones that have adapted to the changing, stressful conditions that our temperate zone has been throwing at them for years. When it comes to trees, those are the hackberry, the honey locust and some varieties of the American elm that are resistant to Dutch elm disease.

"The native plants," Mary says, "are usually the tough ones."

Native vegetation
Native vegetation grows alongside a ditch next to a cornfield owned by Barry Nelson near Lake Park, Minn. Native vegetation buffers reduce erosion and trap sediment before it can flow downstream to a river.
MPR Photo/Dan Gunderson

The Minnesota Department of Natural Resources offers a guide to landscaping with native plants. So do the University of Minnesota's Extension Service and the Minnesota Native Plant Society.

Check the raspberries for rabbits
Matt in Minneapolis called in with a berry problem: His raspberry bushes have been growing in a sunny place, but they're only just puttering along. Compost isn't working. Nothing seems to be working.

Raspberries are native, Mary says — but it's likely that Matt's crop is just young and taking its time to grow. Try fertilizer, full sun and well-drained soil.

And then there are the rabbits. This year, there's been quite a bit of rabbit (and deer) damage on many different plants. Look closely at the canes of the raspberry bushes to make sure they're intact. That might offer a clue as to whether or not rabbits are the culprit.

Every soil needs amending
Especially in vegetable gardens. Vegetables are annual plants and can be heavy feeders.

"I like to add compost," Michelle says. She does it every year. It's better for the plants — she says it makes them much healthier, and she notices that they grow faster. That way, she needs far less fertilizer than if she hadn't added it.

And when you do add fertilizer to your vegetable garden, Mary suggests trying a 5-10-10 grade of fertilizer. (Those numbers — 5-10-10 — refer to the percentages of primary nutrients — nitrogen-phosphate-potash contained in the fertilizer.)

Anything that produces fruit, Mary says, requires more fertilizer. (And don't forget to test the soil as you go.)

Test that soil, too

Mary and Michelle recommend that all gardeners test the soil around their plants.

The University of Minnesota's soil testing lab offers a service for homeowners and others who would like to learn more about the soil in their lawns and gardens.

Follow the instructions for gathering and submitting your soil sample on the lab's website. It takes one to two weeks for the results to make it back to you. From there, you'll be equipped with the information you need to recalibrate the soil in your gardening space.

Don't be afraid to prune
Whether it's barren plum trees or fruitless grape vines, pruning could be the answer, Mary says.

One caller spoke of the four plum trees on his property. For 10 years, they were perfect: Fruit too plentiful to keep up with, on most days. But for the past four years, not a single plum has burst from the trees, despite the fact that the trees themselves are in perfect shape.

Plums, Mary says, are a complicated tree. They need cross-pollination. The lack of bees lately could play a big role, because they're crucial to transferring the pollen among the trees — and if the weather's not right for the bees during pollination time, it might affect the blooms and the fruit.

Look to pruning, then, Mary says. Sometimes, taking up to a third of what's there can shock the trees into fruit-setting. Prune in late winter, Michelle adds — as late as early April.

As for the grapes? A caller in Minneapolis has a backyard full of grapevines that only flower, but don't fruit.

Prune them as hard as possible, Mary says. That ought to get them to produce fruit.

Ward off the pests
Squirrels on honeycrisp apples: Try bagging the apples, Mary says. There are a handful of ways you might do this: Look for the bags used to ward off apple maggots or other insects.

Or — and "I know this sounds like a crazy thing to do," she says — wrap entire branches, so that eventually whole trees are encased, in long strips of mesh so the squirrels can't get to the fruit.

It's a technique used on raspberry bushes, strawberry plants, cherry trees and in commercial vineyards, she says, and it tends to work rather well.

Ants in flower beds: Ants are big this year, Mary says. And they're awfully tough to get rid of.

Your best bet: Try to disturb the mounds. Take a shovel or a rake and break up their piles. Michelle recommends shoveling them out: Dig a hole, remove the mound and replace the soil with a fresh pile.

They won't eat your plants, but they can eventually kill the plants if they burrow their way into the crown. So it's best to get rid of them, if you can. As a last resort, you might try pouring boiling water over the mound, but that could also likely damage the surrounding plants.

Porcupines in trees: One caller suggested using fox urine to discourage the porcupines from visiting the trees. Otherwise, to ensure the trees' survival, inspect the bark all the way around. If there is any bark intact, you might be able to save it. Trees can compartmentalize and heal their own wounds. If there is one-third or more of the bark intact, it very well could be OK, Mary says.

Tomatoes
Tomatoes
MPR Photo/Ambar Espinoza

Grow better tomatoes: A quick list
Skip the milorganite. It's not for vegetables. (But it's great for lawns.)

Use black plastic or black fabric, if you want, to cut down on weeds. (But make sure your soil is moist from the start. Water regularly and at the base of the plant.) Michelle recommends mulch and weeding as an alternative.

Keep tomatoes away from black walnut trees. They're in direct competition with each other and won't grow in tandem. If your tomato leaves turn yellow and fall off, pull off the dying leaves and try to keep the foliage dry (water only the ground and the roots), providing better air circulation. If possible, move your tomato garden several hundred feet from its original spot — it's likely that this is a sign of early blight.

LEARN MORE ABOUT SUMMER GARDENING:

To keep your grass or your garden alive during the summer heat wave without driving your water bill to new heights, follow these tips. (Popular Mechanics)

"The key to success for July is maintenance and good, effective watering. Your local garden centre can give you tips and advice on Summer tasks, but here are some 'must do' jobs for the garden this month." (Bedfordshire News)

"In 2011, University of Minnesota Extension Master Gardeners gave more than 130,000 hours to their communities--a public value worth more than $2.8 million." (University of Minnesota)

After months of rain, many people in the Twin Cities are dealing with water-logged gardens. The storms that passed through last month, pulling down many trees along the way, might also have you considering what larger plants and trees to fill your yard with in the near future.

Gardening experts join The Daily Circuit to talk about the conditions facing area gardeners. They will also take listener questions.

If you're having some problems with your garden or need some advice about starting a new garden, leave your questions in the comments section below.

LEARN MORE ABOUT SUMMER GARDENING:

9 Water-Conserving Tips for Summer Gardening

To keep your grass or your garden alive during the summer heat wave without driving your water bill to new heights, follow these tips. (Popular Mechanics)

July: the lazy days of summer

"The key to success for July is maintenance and good, effective watering. Your local garden centre can give you tips and advice on Summer tasks, but here are some 'must do' jobs for the garden this month." (Bedfordshire News)

Master Gardener

"In 2011, University of Minnesota Extension Master Gardeners gave more than 130,000 hours to their communities--a public value worth more than $2.8 million." (University of Minnesota)