Winterizing trees for the Canadian climate
‘Winterizing’ a fruit tree in cold climates does not need to be complicated. If you have a cold-resistant cultivar with good rootstock, there is no need to make elaborate preparations to protect the tree from the cold. However there are some simple steps that you should take to protect your tree from rodents and breakage during the winter.
Here we will cover the correct method for staking and installing protective spirals. We also have a simple trick that you might want to use in spring, especially in years when you have heavy snow.
Staking is recommended mainly to prevent trees from breakage that can occur in winter and early spring, due to layers of ice forming around the tree. These icy layers form as a result of snow followed by rain, or by a warm period in winter. In spring, it often happens that the snow melts from below, so that the crust of ice descends with the trunk of the tree caught in it. If the tree is young and not supported, this can easily cause the trunk to break.
Similar damage can occur with tree branches that are caught in icy layers in the snow, either on young or mature trees. This can result in the branch being broken. Since we can’t feasibly support all our tree branches with stakes, we have a different method for dealing with this, see below.
The correct way to install a stake
- Use a strong stake: your stake should be strong enough to support the tree properly and should be able to last for at least a few years. We suggest ½ or ¾ inch EMT pipe. You can find this at your local hardware store and request to have it cut into lengths of 5 to 6 feet.
- Plant the stake at least 1 foot deep in the ground, to ensure stability.
- Make sure it is close enough to the tree.
The stake should be right next to the tree, and attached firmly to it. A common mistake is attaching the stake too loosely, or too far from the tree. If there is too big a gap between the stake and the tree, the tree will not have enough support and can still break. In this photo, we are showing the correct way that a stake should be installed.
Note: tightening the attachment to the stake only applies when installing a stake in fall, before winter. If you are installing a stake in spring, you should NOT tie the stake too tightly to the tree, as the tree will need to continue to grow throughout the season. An attachment that is tied too tightly can strangle the trunk or seriously impede its growth. For the same reason, it is important to loosen the attachment to the stake in spring.
Why do trees need protective spirals?
Spirals protect young trees from having their bark eaten by rodents during winter, which may easily kill them. The image to the right shows a tree that has had its bark practically all eaten away by rodents apart from one branch that has been protected with a spiral.
Protecting the trees is more important for some trees than for others, as not all trees are attractive to rodents (although they will probably eat almost anything if there is no other choice and they are very hungry). Those that rodents do seem to find particularly tasty include most types of fruit trees, with the exception of grapevines. Rodent protection is particularly important for grafted trees, as if the bark is eaten below the graft of the tree, the cultivar will be lost. That is why we provide protective spirals for every grafted tree. However, the following non-grafted trees would also benefit from a protective spiral:
- Canada and American Plum
- Oaks (all)
- Seedling plum trees
- Seedling apple trees
- Seedling pear trees
If you would like to add additional spirals to your order, you can find them here at $1.50 each.
Installing a protective spiral
Installing the protective spiral is very simple. It should be done in fall, before the ground freezes – around the month of October is usually a good time for us in zone 4. Simply wrap the spiral around the base of the tree, and bury the bottom of the spiral at least an inch or so in the ground. Sometimes when the tree you are protecting is larger or taller, it might be necessary to use more than one spiral to make sure that the whole base of the tree is covered.
Spreading sand in early spring to prevent branches from breaking
Sometimes if there is very heavy snowfall and the branches of your trees are caught in the snow, it might be necessary to take steps to prevent the icy snow from causing the branches to tear away from the tree as the snow melts.
We have a simple trick for this: simply spread a thin layer of sand, or wood ash, over the area you want to protect. The sand will absorb heat and sunlight, heating the snow underneath it and causing the area to melt faster from above. There are just two important points to take care of to make sure this works correctly:
- Do it at the right time – it should be done in early spring, before the snow starts to melt in earnest, but after the risk of heavy snowfall has passed, so that you don’t end up having to do it repeatedly.
- Make a layer that is just enough to cover the snow, but don’t make it too thick. If you add a thick layer of sand or any other material over the snow, it can end up insulating the snow beneath, which is the opposite of the effect you are looking for.
It could also be useful to do this over the area of your vegetable garden, or anywhere you want the snow to melt faster.
Remove the spiral and loosen the stake
It is important to remember to remove the spiral and loosen the stake in spring once the snow has melted. If you don’t remove the spiral, the tree trunk will not receive any sunlight. As a result, it will be sunburnt when it eventually is exposed to the sun, damaging it in the long run.
As we mentioned above, if you don’t loosen the attachment to the stake in spring, it can cause the tree to grow incorrectly, or even strangle it.