How to Prune a Plum Tree

Pruning a plum tree is an important task, and it’s essential to follow the right methods and to get the timing right too.

Here we look at how to prune a plum tree for the best possible results.

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When a plum tree is taken care of properly, it can produce fruits of the sweetest and juiciest nature. There is nothing as delicious as a ripe summer plum!

But it is important to make sure you keep your plum tree well pruned so that it has the best chance possible of bearing and supporting these lovely fruits. Let’s take a look at when and how to prune a plum tree.

When to prune a plum tree

Before you think about pruning your plum tree, you’ll need to ensure you get the timing right. Contrary to the general rule that says tree pruning should happen during the winter months when the plant is not growing, the opposite applies for the plum tree. Prune a plum tree during the winter, and it could wind up with silver leaf disease. This is a highly undesirable fungal disease that leads to silvering of the leaves and eventually death of the branch.

Plum tree pruning is therefore best carried out early spring to mid-summer. If your plum tree is fairly young, go for late spring pruning. For a more established specimen, opt for mid-summer. However, if your plum tree is newly purchased and only around a year old then you will need to prune it as soon as possible to help it establish a strong branch structure in preparation for supporting its fruit crops when the time comes.

Again avoid winter, but instead go for early March in milder climates, and late March in colder regions.

Plum tree pruning is therefore best carried out early spring to mid-summer

If your plum tree has suffered broken branches in high winds or due to a heavy fruit crop, it is always a good idea to deal with the broken branches immediately. Prune them back to solid, healthy wood straight away. A nice clean cut is much better for the tree than a ragged, open cut.

To learn more about getting the timing right, have a read of our dedicated blog on when to prune a plum tree.

Getting ready to prune your plum tree

In preparation for pruning your plum tree, be sure to have to hand a sharp pair of secateurs, and wait for a dry day.

Always be prepared to make your cuts just above and sloping away from a bud.

Also be ready to mulch the tree, as plum trees need a continuous source of moisture during fruit forming times. Grass cuttings or bark chippings will do the job perfectly. Before you mulch, give the tree a feed of something organic such as bone meal.

How to prune your plum tree

Your plum tree can be trained in one of three main ways: as a bush (the most popular); as a pyramid or as a fan. You can also train plum trees as a cordon where space is limited, although this will require intensive pruning several times a year which is something that plum trees do not respond well to as it can considerably increase susceptibility to infections.

Training and pruning a bush plum tree

Bush training encourages an open-centred tree. Formative pruning of young specimens around one to two years old will lead to an attractive and healthy tree. These plum trees are known as ‘maidens’ and can be ‘feathered’ or ‘unfeathered’. Feathered maidens have side shoots coming off the main stem, whilst unfeathered maidens have only a single stem.

First year pruning involves simply pruning back the stem to around a metre or so in eight. You are aiming in these early stages to get two branches at least growing off the main stem to form a wine goblet shape, so if you see some promising buds in the right position, prune a bit higher if necessary to leave them intact.

For more established plum trees, your core aim is to get rid of weak, crossing, vertical and diseased stems to avoid overcrowding. Any buds you see starting to develop on the lower trunk can be simply rubbed out, and be sure to remove any suckers growing from the roots.

Training and pruning a pyramid plum tree

If you want to keep your plum tree at a size that is more manageable, the pyramid is a good process to follow. Pyramid plums are smaller than bush plums, making them easier to protect with netting so that hungry birds don’t take advantage of your fruit crop.

For young specimens, follow the same advice as for bush plums. Then, in the tree’s first summer, carry out pruning around mid to late July once the shoots have finished growing. Shorten any new branches to around 20cm by cutting above a downward or outward pointing bud. Any side branches can be cut back to a bud at around 15cm. Tie the central stem to a stake for training.

How to prune your plum tree a year on

Shorten the central stem by around two thirds. Do this in April. Continue this process every year until the tree reaches a height of 2.4 metres for St Julien A varieties, or 1.8 metres for Pixy varieties. Once this height is reached you can shorten the central stem by up to 2.5cm every May in order to maintain the tree at the same height.

Always remove any vertical shoots that are competing with the central stem in late June and then, in late July, shorten branch leaders to 20cm to a downward or outward facing bud in the leaf’s axil and reduce the side branches by cutting back to a bud at 15cm.

Training and pruning a fan plum tree

Fan plum trees are trained against walls or fences in a fan-shape. You may purchase fan plum trees as maidens ready for you to train them as a fan, or your tree may already be partly fan trained.

Fan trained trees are attractive additions to any garden or outdoor space. Always plant them a good 15-22.5cm away from your wall or fence on a slight incline towards it. Remember that walls have foundations, so these will need to be avoided, and you will also need to take steps to enrich the soil, which is often poor quality around walls. Choose a wall of at least 2 metres in height, preferably south or south west facing.

Fix up some robust horizontal galvanised wires at 40cm above the ground and at 4-10cm from the wall. Position them 15cm apart.

If you have an unfeathered maiden (see above), in its first spring cut back the main stem to around 40cm leaving three strong buds. In the summer, tie two of the branches that form from these buds to two canes either side. Any other shoots that develop from the central stem can be removed at this point. In the second spring reduce the branches by two thirds to an upward facing bud and remove any more growth from the central stem.

For feathered maidens, follow the same process but as you already have your two branches you can tie these to the canes in the spring.

Pruning a purchased fan plum tree

If you purchase a plum tree that is already part trained as a fan then you will need to remove its central shoot, cutting it right back to two strong branches either side which will also need to be reduced by two thirds if they are weak, or less than that if they are looking strong and starting to branch out. If you leave the central stem then you will end up with a bush. Your aim is to achieve a short tree that has two or more strong arms.

When the summer comes, look at each arm and choose four shoots, one at the tip; two on either upper side and one on the lower side. Tie them in at a 30 degree angle to the main arm. Rub out any shoots that are growing towards the wall or fence. In the following spring, reduce the four branches by a third, where possible cutting down to an upwards facing bud. When the tree is actively growing, secure any re-growth from the branch tips into the wire framework so that the main branches are extended.

Need help pruning your plum tree?

If you have a plum tree that could do with some professional care and attention, perhaps because it has been left to grow into an unruly state, or maybe it has been subject to disease or mis-management in the past, why not talk to TH Trees Ltd? Our highly qualified and exceptionally experienced tree surgeons are at your service with the knowhow and skill you need to get your plum tree looking healthy, and producing plenty of lovely delicious fruit!

For a no-obligation quotation on plum tree pruning, give us a call on 01268 642814 or get in touch here.