Go on, get your hands dirty: Your gardening questions, answered

Buttonbush flower
A bee lands on a buttonbush flower July 7, 2012, at Eloise Butler Wildflower Garden and Bird Sanctuary in Minneapolis.
Jeffrey Thompson MPR News 2012

Gardening is a terrific pastime and can be great for the environment, too. But if you're new to it, all the different kinds of seeds, plants and techniques can seem intimidating.

Don't give up, help is here.

MPR News host Kerri Miller recently sat down with Julie Weisenhorn, a horticulturalist and extension educator at the University of Minnesota, to help answer some of those pressing planting questions.

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When it gets really hot, how can you make sure your plants stay hydrated?

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Watering the soil then placing compost or mulch around your plants can help seal in moisture and cooler temperatures in the soil. Also, it's best to water your plants in the morning so the moisture can absorb into the roots before any evaporation happens.

How can you tell how much water is enough?

The easiest way is to feel the soil. Dig about 6 inches down around the plant with a spade. If the soil is cool and damp you don't need to water them. It's important to note that some flowers wilt in the sun because of heat, but it doesn't necessarily mean they need more water. Those plants should perk back up as temperatures cool.

Should I be worried about the health of trees in my neighborhood?

"Drought is one of the biggest killers of mature trees," Weisenhorn said. It's important to watch for wilting in older trees. While they'll often benefit from lawn watering, it's a good idea to check the soil around the tree for dryness just like you would any other plant. Watering younger trees is especially important as they try to establish their roots. The same goes for shrubs and bushes.

How do you keep hanging basket petunias alive and thriving?

One caller wondered how the petunias at Minneapolis-St. Paul International Airport are so large every year, while the ones he tries to keep at home seem to fail. These plants require a lot of water each day, they also require a lot of space to grow. Your best bet for keeping them alive at home is paying close attention to the amount of water they get, getting a larger container than you normally would and maybe even doing some fertilizing.

What do you do in the case of a watering ban?

Mulching your plants can be a good place to start. Mulch is not necessarily good for ground-nesting bees, so it's important to consider where you mulch, how much you do and if your plants would be able to help other pollinators. You can also reuse water from your house — like cooling water you used to boil vegetables or water you used when canning.

How do you get hydrangeas to flower?

If your hydrangea is only producing leaves, it's possible that it's not getting enough sun, not getting enough nutrients from the soil or you may be pruning it at the wrong time. You can look at what hydrangea you have and see if the producer has any extra tips for care.

When is it best to plant annuals?

You can plant annuals throughout the spring but make sure you plant early in the morning, water them well and try to avoid planting on hot windy days. If that means you have to wait a bit, keep them in a cool shady spot until the time is right.

How can I best handle plants that need sunlight at different intervals?

"Quality of light is as important as length of light," Weisenhorn said. Eastern light, or morning sunlight, is cooler than afternoon sunlight. Consider that when deciding which side of your house to plant on.

What should I do to help my sick/dying plant?

Disease, insects and the weather can take a toll on even well-established plants. Take a look at the root system for signs of damage or dryness. "Sometimes plants just die. We don't really know why all the time," Weisenhorn said. Sometimes you need to make the decision to remove a plant and try again.

What do I do if I think my trees have black mold?

The best thing to do is contact a certified arborist. The International Society of Arboriculture is a good resource for this. "Mature trees do a lot for our landscapes. They cool our landscapes, they create better energy efficiency in our homes, they look beautiful, they add property value. And so when you do see issues with them I think you do need the pro to come in and assess them properly," said Weisenhorn.

How do I combat bugs on my plants?

First, identify the plant and the bug. You need to specialize your approach based on the pest — for example, a pesticide won't do anything to stop a mite. "Sometimes there's nothing to do about it," Weisenhorn. If it's just cosmetic damage being done to the plants, it might be best to let it go, "that's part of gardening."

How do I plant a pollinator-friendly garden?

It can be a complicated process, but luckily there are lots of resources to help. On the U of M Extension program's website there is a whole section dedicated to the topic. MPR News has also done some previous reporting on pollinator friendly gardens, which you can read here.

Have your own gardening question? Fill out the form below and MPR News will try to track down the answer:

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