Fruit gardening is a challenge even under the best of conditions. You can’t predict rain, you can’t always protect from insect invasions; you fight a constant war against thieving birds; and the weeds threaten to overtake your orchard or berry patch pretty much on a continuous basis. For northern gardeners, add winter weather to that list of challenges.
I can understand birds. I feel like I have some measure of control against the weeds (let’s face it, laziness might have a wee bit to do with the state of my berry patch). However, I have no control over the temperatures, and when gardening in zone 4, those temperatures can drop significantly below zero. Growing fruit in norther zones is simply a struggle – but winterization of your trees and bushes can help! This post gives a quick rundown of the basic winter-preparation tasks you can do to protect your fruit garden from winter damage.
COLD-PROTECTION FOR FRUIT TREES: INSULATE ROOTS WITH MULCH
The first thing you can do to winterize fruit trees and berry bushes is making sure the roots are protected. Adding mulch around the base of the tree or shrub can have a huge impact on soil warmth. For gardeners in northern zones that get a lot of thick snow, those snowdrifts will only support your efforts by adding an extra layer of insulation – but since you can’t always predict snowfall, get a jump start on the winter by mounding up a few inches yourself. My personal rule of thumb for shrubs is to mulch out to the dripline of the bush, to ensure the bulk of the roots are protected. For larger trees this obviously is not economically feasible, but you know what? the larger trees have typically survived several winters already, and their roots should (should!) be better able to survive a rough patch. For newly planted “whip” saplings that don’t have much of a dripline to speak of, mulch it as you would if the tree was one year older with established branches and a dripline.
One caveat: you MUST be very careful not to mound up mulch against the base of the tree itself. Give the trunk of the tree a little moat of bare ground between the bark and the mulch material. This protects against rodents, unwanted suckers from the roots, and insect invasions.
SUN PROTECTION FOR FRUIT TREES & SHRUBS:
I know it doesn’t make sense, but the warmth of the sun is bad news for your fruit garden during the dead of winter. A dormant tree is as protected as it can be from frigid winter weather; all the cells are sleeping, conserving energy, and hiding away from the cold. When golden afternoon sunlight hits the tree on a sunny January afternoon, those rays can signal the tree to wake up – and prematurely believing it is spring, the tree tries to emerge from dormancy, only to be decimated by icy temperatures. Oddly enough, I’ve heard that more trees are killed as a result of winter sunlight than they are by winter temperatures. Sometimes the tree isn’t outright killed, but you’ll see the damage resulting from this timing mistake; splits along the trunk usually point to an attempt by the tree to wake up, which promptly destroys any “awake” cells and rips that section of bark wide open (an open door for disease too, I might add).
To protect your trees and shrubs, find a way to block the sunlight. I’ve just recently started experimenting with tree tubes; the jury is still out, but the white plastic tubes certainly don’t seem to be doing any harm. You can also buy wraps or make some yourself out of any material that will effectively block light (and this means no black materials that will soak up the sun’s heat, transfer it to the tree, and cause even more problems!).
Don’t forget that you will need to remove clingy wraps in the springtime. You don’t want to strangle the tree with too much love.
ANIMAL PROTECTION FOR FRUIT TREES AND SHRUBS
In addition to the weather, you have to consider the side-effects of winter on your poor little plants. Unfortunately, when cold weather hits, most of the food supply for herbivores – think rabbits and deer – is killed or effectively buried under mounds of fluffy new snow. Now, in theory I’ve got nothing against Bambi and Thumper… but I do get annoyed when they leave their comfortable woods and chew on the tender buds and bark of MY trees because they taste better than the wild flora out in the forest. All they need is one night to take a tree from promising young transplant to completely stripped dead twig. Grump.
Similarly to wrapping for sun protection, you need to find some way to protect the tree from animal nibbles. Don’t make the mistake of protecting from rabbits by merely wrapping the bottom two feet of the tree – you MUST wrap higher, because as snow piles up over the winter, that snow becomes an automatic step-stool for rabbits. In my area, the snow can routinely get two feet deep, which means I must wrap the bottom four feet of the tree to protect from rabbit attacks!
Deer have a much higher reach and it’s harder to wrap in a way that deters a deer; on their hind legs, they can reach almost as high as I can, so wrapping doesn’t do a lot. What you can do is construct a temporary fence around the tree that keeps them far enough back that they can’t reach… or, if you’re a total redneck like me, you can protect young trees and shrubs by taking a 55-gallon oil drum with the top and bottom knocked out and dropping it right over the top of your tree. In really desperate situations where the deer were STILL nibbling on the top of the tree that had emerged from the drum, I took a long stick slightly longer than the sapling, speared it into the ground right next to the tree, and put a five-gallon-bucket upside down on the stick where it would cover the top of the tree above the coverage line of the barrel. It looks absolutely ridiculous, but it works.
OTHER LEARNING RESOURCES FOR WINTERIZING FRUIT TREES
As always, there’s more to learn than you can find in just one blog post! If you are looking for additional resources on winterizing fruit trees and shrubs for northern-zone winters, I always default to county extension offices and universities (and obviously for this topic, you’d look for expertise from a university in a state with cold hardiness zones). One of my favorite resources I would recommend is a winterization article from the University of Minnesota Extension Office. Other states have some information (Illinois Extension has an article mostly focused on wrapping trees, as does the University of South Dakota). There are plenty of other resources out there!
Not sure what fruit trees will work in your zone? Read up on how to find cold-hardy fruit trees for zone 4 and colder.