Pruning apple trees is top of mind at this time of year. They are some of the most popular, reliable, and commonly grown fruit trees.
Apples grow in most climates, and there are hundreds of varieties available. It’s possible to harvest fresh apples from early summer through to mid-winter, and they also store well, making them effectively available all year long.
Can you tell we love apples? We do, so much that we’ve written this blog with everything you need to know about growing apples (the organic way).
All apple and pear trees vary in their fruitfulness and growth habit. This is due to a combination of variety, rootstock, climate and situation. Get to know your tree and vary your pruning in response to the individual tree.
The basics of pruning apple trees is the same as pruning other fruit trees. We won’t go into it in depth here because we’ve already explained it in this blog. However, there are a couple of extra factors you need to consider about apple trees.
The first is that some varieties of apples are spur bearers and some are tip bearers, and they need to be pruned differently. More on that in a moment.
The other factor that can influence apple tree pruning is that they can be grown on lots of different rootstocks, so let’s start there.
Dwarfing vs full-size trees
Apple trees are grafted onto apple rootstock, and there are many different types available. The rootstock determines the ultimate size your apple tree will grow. It can also give it other characteristics such as disease resistance.
The largest type of rootstock available is a seedling (literally, grown from seed). These rootstocks develop into long-lived and resilient trees, with good drought and flood resistance. They can grow up to 5 to 6 metres tall (or bigger), though the size can be kept smaller with appropriate pruning.
All other rootstocks are smaller than seedlings. Some of the more commonly available semi-dwarfing and dwarfing rootstocks include:
- MM111 (about 80% the size of a seedling)
- MM106 (about 70%)
- MM102 (about 55%) – this is the dwarfing rootstock we use here on the farm in Carr’s Organic Fruit Tree Nursery
- M26 (about 40%)
- M9 (about 25%), and
- M27 (about 15%)
Before you start to prune your apple tree, it’s good to know what rootstock it’s on if possible. This can help you decide what shape you’re aiming for.
If you’re not sure, and it’s obvious that your tree is not a dwarf, it’s usually easiest to prune it into a vase shape.
The larger and medium-sized rootstocks are well suited to vase-shaped trees. The middle-sized rootstocks lend themselves well to espaliers and fans, and the smaller rootstocks work well on trellis systems, or as free-standing pyramids.
However, it’s also possible to grow larger trees on trellis, you just need to have a trellis that’s big enough to take it!
Tip bearing vs spur bearing: understanding how apple trees grow
Most apples and pears are spur-bearers. This means they bear fruit on wood that is 2-years-old or older. This wood is in the form of short fruit-bearing shoots known as spurs.
Spur-bearing varieties tend to have slow-growing leafy shoots, and a mixed terminal bud (both leaves and flowers). They are best for espaliers, fans, and trellis systems. Both tip and spur bearing varieties suit vase-shaped trees.
Far fewer varieties are tip-bearers, which bear fruit as clusters near the tips of longer shoots, They have a lot less spurs and greater lengths of bare wood between the buds and shoots.
Some varieties are both tip and spur bearing.
It’s good to know what type of apple or pear tree you have before you start pruning. If you’re not sure, wait until the tree flowers in spring to decide where to prune.
How to prune spur-bearing apples
- Old spurs have few fruit buds, so on older trees, thin any spurs that have become overcrowded. Only remove them completely if there are replacement young shoots nearby.
- Laterals can be shortened to encourage spurs forming. Shorten the laterals on each main branch to about 5 or 6 buds for strong laterals, or 2 or 3 buds for weaker laterals. Cut them back neatly to a bud. This will encourage the development of new side shoots and spurs. Short laterals can be left unpruned.
- On a 2 year old spur (i.e. a lateral that was shortened the previous year), it will most likely have branched into 2 or 3 new laterals. Shorten each of them, as this will help to encourage the development of spurs.
- On really large, vigorous trees, it’s impractical to shorten every single lateral. Make larger pruning cuts to remove part or all of some of the more crowded branches.
- Horizontal wood grows spurs and develops fruit buds more easily than vertical wood.
How to prune tip-bearing apples
- Identify the new growth (laterals, or side shoots) on your tree. They are usually a different colour to the older wood. The buds on the end of these new shoots are terminal (or apical) buds. This is the main place fruit will grow on your tree in the coming season. It’s important not to cut too many of these off when pruning, or your tree won’t have any fruit.
- Fruit buds are fat and furry, leaf buds are slender and smooth.
- On mature trees that have been fruiting, use renewal pruning to remove a proportion of older fruiting laterals back to a new side shoot to favour new growth. You can also shorten them to one or two buds, or remove them completely if there are plenty of new replacement shoots.
- Unlike spur bearing varieties where most or all laterals are shortened, leave all the other laterals unpruned on tip-bearing varieties, as they will carry this year’s fruit crop.
When is the best time to prune?
As we often say, there’s no right or wrong with pruning, just cuts and consequences. They can be pruned at any time of year – you’ll just get slightly different consequences.
Apple and pear trees are normally pruned in winter, and it’s certainly easier to see what you’re doing when the trees have no leaves. If possible, try to finish pruning before the trees start flowering (unless you’re waiting for the flowers to see where to prune your tree!).
Apples and pears that are growing on more formally trained systems such as espalier, fan, or trellis will probably also need summer pruning.
This helps to control the strong upright growths (called ‘watershoots’) that are often produced by horizontal limbs. These new laterals should be shortened back to three leaves above the basal cluster of leaves, or if they are growing from an existing lateral or spur, you may want to prune them back even harder.