Pruning Apple Trees in Alberta

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How to Prune Apple Trees in Alberta

Prune your apple tree.

When to Prune: The best time to prune is when the tree is dormant. Dormant pruning removes some growing points to increase the root resources to the remaining buds. In Alberta, this is done during the in March or early April, prior to leaf-out in the spring. Our winters are too severe, and the snow may be too deep to prune in the fall or during late winter.

Understand and Protect Your Tree: At the end of each growing season, the top of the tree and the root system are in balance. To encourage proper dormancy, I would recommend that you only fertilize your tree in early spring, and reduce water to your tree by mid August, to encourage it to go dormant in a timely fashion. You do not want to encourage lush growth late in the season! “Water it in” after the leaves start to turn yellow after a killing frost late in the fall to protect the roots from dry soil and penetrating frost.

I do not recommend summer pruning! When you remove branches and leaves when they are actively growing, you cut out the accumulated energy that the tree has created over the growing season before fall. The tree will not have a chance to move that energy from the tops to the roots for winter; the net effect is a depletion of tree root reserves that is results in reduced vigour or lack of hardiness for the following season.

Goals of Pruning: There are normally two goals when pruning an apple tree: Training young trees to encourage a strong, solid framework to support early production and branches capable of supporting heavy crops in future years, or pruning mature apple trees to maintain shape and encourage apple production.

Young tree scaffold branches.

Young Apple Trees
The day apple trees are planted is the day to begin to train and prune them for future fruit production. Too often apple trees are planted and left untended for several years. This neglect results in poor growth, delayed and under-sized fruiting.

A new apple tree will usually be either a 1 m (3 -4 foot) whip (it has no branches), or a 1-2 M (6 foot ) tall young tree with several branches. This is assuming you have not purchased a dwarf variety.

If you have recently purchased, or own a young tree, and need to determine its shape as a mature tree, this is how to go about it!

Central Leader
Training to a central leader produces a tree that has a pyramid shape. If your newly planted tree is a whip (it has no branches and looks like a long stick) snip the tip at a height of about 90 cm (36 inches). This will stimulate branches to grow along the trunk, and the topmost bud will become the central leader.

For a new tree that already has side branches, cut off the tallest growing tip (on the leader). Cut off any branches along the trunk between the ground and 61 cm (24 inches) high. Cut back any remaining side branches to 5-10 cm (2 to 4 inches), leaving no more than 2 buds on each branch stub.

First Summer:
Make sure the top shoot becomes the leader. Pinch back all other shoots competing for the top spot at the top!

First Winter:
If there has been a lot of new growth, choose 3 to 5 branches for the first set of scaffold branches. These branches should spiral around the trunk with about 10 cm (4 inches) vertical distance between each branch.

Cut off the other side branches and any vertical branches that may compete with the leader. Prune back the main leader shoot, but keep it as the highest part of the tree to maintain your pyramid shape.

Second Summer:
Make sure that the top shoot is growing vertically, cut off any competing shoots.

Second Winter:
Select another set of scaffold branches 60 cm -90 cm (2 to 3 feet ) higher than the first set. If the tree didn’t grow enough the second year, do this the third winter.

Each year after this: Keep doing the above until you have 3 or 4 sets of scaffold branches. Then simply keep that shape by pruning out water-sprouts and any crossing, diseased, or unwanted branches. Try to keep the lower branches longer than the upper ones to maintain the shape.

Mature Apple Trees:
Prune mature apple trees to maintain shape and encourage fruit production. The only growth you ever want to prune or remove during the summer months, when the tree is actively growing, is a sucker, (shoots coming from the roots).

Here is a list of types of branches you always want to prune out when the tree is dormant in March or April:
 Stubs or broken branches
 Downward-growing branches
 Rubbing or criss-crossing branches
 Upward growing interior branches
 Competing leaders
 Narrow crotches
 Whorls

Pruning Mature Apple Trees
Full-size, mature trees usually already have their shape determined, so it really comes down to maintaining their shape and size. Hopefully, their scaffold branches were well chosen at the beginning of the process!

Start with removing broken or diseased branches, rubbing or crossing limbs, weak stems, and any branches growing inward to the tree’s center. Also prune out any growing vertically or straight down, thin out enough new growth to allow light to filter into the canopy when the tree has leafed out so the fruit can ripen and color properly.

Shorten any branches that are too long to avoid leggy growth, shape tree evenly and remember apples flower and fruit on old wood, so head back new growth to direct energy back into the flowers and fruit.

Also, if in the past years too many apples have formed and crowded each other out, you can thin the spurs to only a few per branch. This will allow enough light and air to circulate around to avoid diseases and small, puny fruit.

Corrective Pruning for Neglected Apple Trees
You may have purchased a house where an apple tree was planted on the property several years ago. Often, the previous owners did not take the time to properly prune the tree. The tree has become bushy, diseased or weak and will produce very poor quality apples.

The general rule of thumb is not to remove more than 30% of the branches any given season, so this is at least a three – four year process! Excessive removal of branches will result in water-sprouts or suckers all over the tree. The main objective in pruning such a tree is to try to open up the interior to allow good light penetration to the leaves.

The first step is to inspect for dead or diseased branches. Check them carefully for signs of the disease Fireblight. Telltale dead branches will have dead tips with sunken lesions along the branches, or shrunken, scorched looking bark.

Make sure you have a bucket with some 10% bleach solution in water to dip your pruners into between cuts. You will spread the disease from branch to branch if you do not. Diseased branches must be cut back 45 cm (18 inches) from the dead wood. If the disease has entered the main trunk, you must remove and dispose of the entire tree, or it will act as a carrier for the entire neighbourhood. Sorry!

If this is not the case, then begin with corrective pruning! Remove all the upright, vigorous growing shoots at their base that are shading the interior. As with the young apple trees, it is necessary to select 3 to 5 lower scaffold branches with good crotch angles and spaced around the tree.

Limbs with poor angles, and excess scaffold limbs, should be removed at their collar (base where they attach to the main branch).

Pruning Dwarf Apple Trees

Dwarf apples are relatively easy to prune because of their small size. Most dwarf apple trees aren’t much taller than 2 M (6-8 feet). This means in most cases, you won’t need of a ladder, which makes the pruning job faster, easier and safer.

Prune dwarf varieties every year the same plan that you would use to prune a full-size tree.

Maintain its height by cutting back the central leader by 60 cm (2 feet), depending on the vigour of the tree, to a strong lateral branch.

Open up the canopy of your tree so that when it is leafed out sunlight and air can still easily penetrate its center. This helps prevent disease, reduces pests and encourages proper coloring of the fruit as it ripens.

Thin old-growth spurs that are growing too closely together. Apples will form on old-growth spurs–thinning them now helps prevent too much fruit from setting on later.

Remove and dispose of all cuttings, especially diseased branches.

In future years, you may have to repeat this to keep the tree the height you want.