MANITOULIN – Canadian winters can be hard on even the hardiest of trees and shrubs, especially so for those more sensitive, decorative or fruit bearing versions. But there are a few things you can do to give your trees and shrubs a bit of an edge when Jack Frost’s cold breath comes calling. The Expositor caught up with a couple of Island nurseries to discover what the experts think should be on any gardener’s best practices list for this fall.
“I think one of the key things, especially for freshly planted trees and shrubs is to ensure they are well watered-in,” said Cheryl Harper of Har-Cor Greenhouse on Bidwell Road. “But don’t overwater, just ensure that the soil around the tree is moist.”
Keep the water where it needs to be by mulching around the tree base (but not up to it) out to the dripline, where the tips of the branches extend.
Frozen soil prevents plants from taking up water to replace the moisture lost from evaporation and transpiration, so getting them a good drink before the frosts sets in deep is important.
Tammy Teege from JD’s Garden Centre in Tehkummah suggests wrapping the tree trunk with a couple of layers of burlap to help protect your trees from the ravages of the winter winds. Cold winds are usually dry winds and even though the temperature drops, the winter’s sun can dry out or burn conifer needles and broadleaf evergreen foliage. Those plants continue to give off water vapor even during the winter.
“Wrap the burlap from the base of the tree up at least three feet or so and use twine to put it in place,” adds Ms. Harper. “If it is a smaller tree or a shrub, you can try ‘tenting’ it under boards or burlap.”
Wrapping before the worst of winter arrives is a good idea, but don’t leave off too long. Early cold spells can damage those plant tissues that haven’t had a chance to harden off for the winter.
Anyone familiar with Island winters knows they can be tricksy things, with thaws appearing on the heels of subarctic temperatures. Those midwinter thaws can wake up your plants, making them emerge from dormancy too early—those tender new shoots becoming easy prey for the next cold snap.
Those alternating freeze/thaw cycles can even cause frost heaves, lifting the newly planted up out of the ground’s embrace and exposing roots exposed to the drying ravages of wind and sun.
“That winter sun can heat up dark tree barks and when the temperature drops again, they can freeze and crack when temperatures drop after the sun sets.
“As for whatever is left on the fruit trees, the deer usually takes care of that,” laughs Ms. Harper. But mice, rabbits and other animals turn to bark, leaves and twigs as other food becomes scarce during long, cold winters, so the burlap wrappings and other rodent shields can be a good idea as well.
The key to keeping your plants vibrant when the warm weather returns, you need to ensure your plants are hale and hearty long before the cold weather comes calling. If your tree goes into the winter already reeling from insufficient light, poor watering or nutrients, or heavily damaged from insects and disease, you might be dismayed come spring—so start your preparation during the growing season and on into autumn.
While some people prune in the fall, most experts agree, don’t prune after midsummer as pruning stimulates new growth and delays dormancy—and those new shoots are as vulnerable as a newborn babe.
Stop fertilizing plants six weeks before the first fall frost. This will help your plants to “harden off” properly. A little tough love is called for here.
So water plants well throughout fall, right up until the ground freezes, and make sure the water penetrates a foot to a foot and a half deep to ensure it reaches the root zone. Pay special attention to young or newly planted trees, as they will be less able to obtaining water in their growing environment. The key to survival is giving trees adequate moisture before winter freezes the world around them.
When mulching, lay the material down well around the tree trunk, but don’t let it touch the bark of the tree itself, advises Ms. Harper. You can even put down a weed barrier before piling on the mulch to help nestle your roots in a nice cozy, moist environment. Piled up on the bark mulch is just an invitation to mice, moles and insects to come munch.
While tree guards are great for discouraging gourmet rodents, be sure to remove them come spring so they don’t encourage disease, insects or rot.
When it comes to your evergreens, including boxwood, holly rhododendron and most conifer species winter burn becomes an issue. It is often mistaken for an infectious disease or damage from frigid temperatures. This actually comes about from warm weather in the early spring, before the ground has warmed up enough to allow evergreens to sip the groundwater. Since these trees and shrubs lose water through transpiration, dehydration sets in. Transpiration is where water leaves the plant through openings in its leaves, etc.; plants lose up to 90 percent of their water through transpiration.
Windbreaks and wrapping helps with this issue, while there are also various types anti-transpiration applications, these tend to be more trouble than they are worth as they have shown limited effectiveness, are short-lived and need to be applied every two or three weeks.
“You should get rid of dead branches and anything that is obviously damages,” advises Ms. Harper. Getting rid of suckers (branches sprouting from the base of the tree) is also a wise idea, letting the tree’s resources go to the more mature upper branches—but be judicious in any pruning, stick to the stuff that is already dead or dying. But if a branch is drooping to the ground, trim that back as it can be a superhighway up the tree for ravaging insects.
With care and diligence you can give your trees a great fighting chance to come out with leaves and flowers blossoming when the warm weather finally returns for good.
