How To Care for Plants and Trees in Minnesota’s Cold Climate

We probably don’t need to tell you that our harsh Minnesota winters wreak havoc on landscape plants. But what you might not know is that there are plenty of ways to protect your plants so that they experience less damage during the winter season, and are ready to come back to life in the spring. Here are 10 ways to care for your plants, shrubs, and trees in Minnesota’s cold winter climate. 

1. Use Mulch

Roots of most trees in Minnesota die at temperatures lower than 0 degrees and up to 10 degrees F. So how do trees survive Minnesota’s below-zero winter months? The answer is soil temperature, which is usually higher than the temperature above ground. If you want to help protect your plants’ roots during winter, you can insulate the soil using mulch. Three to four inches of shredded wood mulch should do the trick.

2. Choose Plants Wisely 

One of the best preventative measures you can take to prepare your garden for winter is to choose hardy plants that are already adapted to Minnesota’s climate. These plants are much more likely to survive the cold winter months. Here are some examples of shrubs and trees that can stand up to our freezing temps: 

  • Winterberry: This Minnesota shrub is known for its colorful, cherry-red fruit. 
  • Witch Hazel (Winter Bloom): This deciduous tree/shrub has a fragrant smell in the summer and produces yellow and red flowers in the winter.
  • Red Twig Dogwood: This beautiful tree has red branches all year round and during the spring and summer it produces leaves. 
  • Christmas Rose: This evergreen perennial produces beautiful white flowers in late December through early spring. 
  • Snowdrops: These delicate flowers are simply made for the snow, and flower in late winter.Give plants an Inch of Moisture Every Week 

Water your plants and trees regularly during the summer months to ensure they are well hydrated prior to winter. Try to give them all an inch of moisture every week right up until the ground freezes. This preventative practice will keep the ground moist, which reduces the chance of damage like sunscald (more on that below) and frost penetration of the soil. And, as we mentioned earlier, moist soil retains more warmth than dry or sandy soils, so preventative watering can help keep the roots of your plants and trees warm during winter. 

3. Prune at the Right Time

It’s best practice to prune trees and shrubs in the late winter or early spring, because this is a time when temperatures are still cold and the plants are still dormant, but spring is just around the corner. Pruning within this window will ensure that your plants are wounded for the least amount of time, as they’ll heal quickly when the temperatures warm. Pruning your trees and shrubs prior to this will make them more susceptible to low-temperature injury. 

4. Protect Trees From Sunscald

Young trees, trees that have only been planted recently, and trees with thin bark are all more susceptible to the negative effects of the winter sun, known as sunscald. Characterized by an elongated area of dead, cracked, or sunken bark, sunscald occurs when tree bark is warmed and “activated” by the winter sun, only to be quickly exposed to freezing temperatures again at night. To eliminate sudden warming of tree bark, encircle the trunk of all susceptible trees in white plastic tubes up to their lowest branch. This will insulate the tree and keep the sun off its bark.

5. Use Blankets 

Protect your plants from frost and snowfall by covering them with blankets, sheets, or burlap. Fabric coverings work best because they allow excess moisture to escape while still protecting your plants from frost. Use a hoop or stakes to support the fabric covering and make sure the cover reaches all the way to the ground. This will help trap the warm air inside the canopy. 

6. Maximize Sunlight 

Ensuring that your plants have plenty of sunlight during the winter months will help them to stay warm and vigorous. So if you’re using a fabric cover to protect your plants from frost, make sure to remove them when the sun is shining and the threat of frost has passed. Keeping your trees properly pruned will also allow more sunlight to reach the surrounding plants. 

7. Fertilize 

Did you know that the roots of trees and plants often continue to grow, even in winter? That’s why you’ll want to fertilize your plants and trees in the fall to give them an extra nutrient boost before winter sets in. Fertilizing before the ground freezes will make your trees and plants stronger, sturdier, and more durable. Look for leaf color changes and the start of leaf drop to ensure you don’t fertilize too early.

8. Pest Control 

Winter is a great time for pest control. Certain pests that wreak havoc on plants during the warmer months become dormant in winter months and are easily accessible. For example, spider mites and codling moth grubs hide near the tree trunks in little crevices where they can stay as warm. Aphids will lay eggs in trees that will stay dormant through the winter and hatch in spring. You can treat each of these by applying organic, oil-based washing sprays (otherwise known as a winter wash or dormant spray) to eliminate pests hiding in crevices. You can also apply a glue band around the trunk of your trees to trap pests as they crawl upward.

9. Minimize Animal Damage 

Mice, rabbits, voles and deer feed on twigs, bark, leaves and stems in winter. Putting up a physical barrier around the plant will keep animals from gnawing on your trees and shrubs. Use a ¼-inch mesh hardware cloth as a fence around your shrubs to keep animals out. To protect your trees, encircle the hardware cloth about 6 inches away from the trunk. The cylinder should be at least 1 foot above the highest expected snowfall. 

Think Your Garden Needs Professional Help?

If you want to give your trees and plants the best chance of survival during the winter, call the professionals at McDonough Landscaping. With one of our maintenance packages, we can monitor your plant’s health for any signs of winter damage. We also offer services such as mulching and snow removal. Contact us online or give us a call at (651) 755-7901 to talk to us about your landscaping needs. We look forward to helping you protect your plants and landscape this winter!

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