A Guide to Winter Pruning for Apples and Pears

A Guide to Winter Pruning for Apples and Pears

For the ornamental gardener, there was a time you could put away the mower in October and, save for maybe raking up the last of the fallen leaves, be safe in the knowledge that the garden was put to bed for the winter. Nothing to do more taxing than looking through the seed catalogues, choosing old favourites and new varieties to try the following year, and perhaps keeping an eye on some pots of fuchsia cuttings lined up on the spare bedroom window. For the fruit grower, winter is arguably busier than summer. The last of the top fruits are to be picked and stored, greasebands need to be checked and replaced, winter washes applied to keep the trees clean and healthy. Probably the most important job of all though, is the winter prune for apple and pear trees.

Annual winter pruning is one of the most important jobs for anyone growing apple or pear trees, and for several reasons:

It helps form a sturdy tree. Formative pruning makes sure the tree is evenly balanced, with a strong framework of branches which will not break easily in wind or cause the tree to topple.

It helps ensure a healthy tree. Removing dead or diseased branches removes potentially fatal sources of infection, and opening up air circulation reduces the risk of fungal diseases.

It promotes a fruitful tree. Regular pruning helps encourage the production of fruiting spurs, as well as allowing better sunlight penetration to improve fruit ripening.

Finally, and possibly most importantly, it keeps the size of the tree under control.

Winter Pruning, the basics:

1 Prune out dead, diseased or damaged wood. Normally you would do this as part of your winter prune, but can actually be done at any time of year. In fact, it is best to do this as soon as you notice the damage, so if you spot a little canker on the branches, or a limb has been broken in high winds, prune back to a healthy branch or bud as soon as you can. Damaged branches are one of the main entry routes for diseases such as canker, so clean them up and help protect your tree.

2 Remove any branches which are crossing and rubbing. Not only will the bark become damaged, allowing disease to enter, but it is also a sign of congested growth. Thinning branches out will give better air circulation and improve the health of the tree and the quality of the crop.

3 Remove any branches growing into the centre of the tree. For most fruit trees, we are aiming for a nice open centre, almost like a wine glass. This again allows better air circulation and sunlight to get to all the fruit. Young pear trees in particular are prone to growing in a narrow, upright fashion until they broaden out with age, so for pears this step is probably the most important.

Formative pruning and apical dominance.

I do sometimes like to throw in the occasional bit of botany into these articles. Nothing to frighten the horses, but a basic understanding of the science behind our gardening helps us to grasp why we do something, and hopefully also how to do a task correctly. Blindly following diagrams marked ‘prune here’ is all well and good, but knowing why we do it that way will make us a better and more productive gardener in the long run.

Winter printing, especially of young trees, encourages new growth. Left unpruned, the bud at the end of any branch or the main stem (called the terminal or apical bud) is dominant. Trees have evolved over millions of years to have to compete for light and air in dense crowded forests, and only the strongest would survive. Sending out strong long shoots would ensure that the tree could get to the sunlight before its neighbours, and so produce its own energy through photosynthesis. The apical bud produces a hormone called auxin, which inhibits buds further down the stem from growing, ensuring all the plant’s energy goes to the terminal bud. By pruning this bud off in winter, the amount of auxin is reduced, and so buds further down the stem can start to grow away.

This little bit of science underpins a huge amount of why we prune fruit trees. Long whippy growth is often unproductive, prone to wind damage, and just takes up too much space. Prune in winter and we encourage more branching, which should give us bigger and better crops in future years.

The main pruning should be carried out in December or January, and you first need to carry out the 3 essential steps outlined already. Once that has been done, the main task is to try and form a nice balanced open shape. It’s good practice not just to cut off the apical bud, but to prune back the branches by about 25-35% of the previous season's growth and always prune to a bud on the outside of the branch. This should get some outward growth forming, which in turn will give us the fruiting spurs we are looking for.

Rejuvenating old trees.

If you have a tree that has maybe been neglected or has gotten out of hand, the best advice is to try and take things slowly. Don’t try and hard prune the whole tree in one go. Depending how hard you prune, at worst the shock can be enough to kill the tree, but at best you’ll end up with lots of weak regrowth so the tree will resemble a hedgehog. Hard pruning in winter tends to encourage ‘water shoots’, the plethora of vertical non-productive growth which can take a long time to get back into shape. Instead, start with the three essential steps (always!), and then reassess. Aim to prune the tree back into shape gradually over the course of 3 or 4 years, pruning back 25% of the tree hard, and leave the rest alone (or at most a very light prune). The next winter, take another quarter of the tree back hard. Done this way, over a long period of time, you shouldn’t have too many problems with water shoots – if you do, rub out the young shoots as soon as they start to appear in Spring.