When to prune olive trees - these are the only months you should be doing it, say gardening experts

If you’re in the process of planning and designing your dream garden or are looking to add a few trees to your space to provide some much-needed greenery, olive trees work just as well indoors as they do outdoors. But they do require some care and attention to keep them looking their best, including knowing when to prune them.

As one of the best trees for small gardens, they’re relatively low maintenance and an elegant addition to any garden.

Pruning olive trees is essential to retain their shape, but knowing when to prune is just as important. So, if you’ve been wondering when you should be getting your pruning shears or secateurs out, the experts have revealed exactly when to prune your olive tree and just as crucially, when not to prune.

What month do you prune olive trees?

There are only a few months each year when you should be pruning your olive trees, the experts concur. ‘The best time to prune olive trees is late winter to early spring, typically between February and April,’ Morris proposes. ‘Pruning during this period allows the tree time to heal before the growing season starts, minimising stress and promoting vigorous growth.’

Georgina O'Grady, Managing Director at Evergreen Direct, says ‘I've found that the best time for olive tree pruning is late winter to early spring, once the cold weather starts to die down. In my opinion, this period is perfect for encouraging new growth while reducing the risk of frost damage.’

If it is still relatively cold and spring-like in May, which let’s face it, it could very well be here in the UK, you could potentially wait until early May but this would be the latest in the year that you’d want to prune your olive tree.

When should olive trees not be pruned?

There are actually a number of months of the year when you should not be pruning your olive tree. As you might expect, ‘it should not be pruned in the winter months because in case of freezing temperatures, it could cause serious damage,’ Leonardo and Domenico Musceo, Gardening Specialists on Airtasker, caution.

With both Leonardo and Domenico hailing from Puglia in Italy, an area which has some of the highest amounts of olive trees and olive oil production in the world, they also recommend putting your secateurs or pruning shears down during the late summer months. Avoid ‘during the summer while it still has fruit,’ they say, ‘because it could cause stress to the tree and also expose the tree to cold damage for the winter.’

Georgina has a similar warning. ‘In my experience, it's best to avoid pruning olive trees in the hot summer and autumn months, as this is when they start to go dormant,’ she explains. While Jane Dobbs, Team Lead Gardening at Allan’s Gardeners, agrees that ‘pruning olive trees in late autumn or early winter isn't a good idea, as when you prune during this time, the cuts and new growth are more vulnerable to frost damage.’

While pruning make sure you examine the tree for any ‘dead, diseased or damaged branches,’ Morris Hankinson, Director of Hopes Grove Nurseries, suggests. ‘Look for areas where branches are crossing or rubbing against each other. A common symptom to spot is the olive knot, where the branches look swollen, have knotty growths on branches and twigs, and are oozing sap.’

Once you’ve identified these, you can start by cutting out these sections, making a clean cut just above a healthy bud. ‘This will improve the overall health of the tree and prevent the spread of disease,’ Morris adds.

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FAQs

Can you prune an olive tree too hard?

Believe it or not, you can actually prune an olive tree too hard or too much and this can cause a variety of different issues for the evergreen Mediterranean plant. For example, ‘over-pruning can stress the tree, reduce fruit production and make it more vulnerable to diseases and pests,’ Morris warns.

‘To avoid shocking the tree, limit the removal to no more than 25% of the canopy in a single year,’ he recommends.

How do I keep my olive tree bushy?

You also don’t want to trim your olive tree so much that it starts to look sparse or bare. Most of us will probably like them to look somewhat bushy, and ‘regular pruning is the key to keeping olive trees bushy and dense,’ Jane explains.

‘When new growth starts, pinch it back. By doing this, the tree produces more lateral branches, which makes it look bushier,’ she continues. You’ll also want to ensure that it gets an adequate amount of light, as your tree can get sparse if it doesn’t receive enough light throughout the day. And you do have to judge how much water to give it, as ‘overwatering and underwatering can stress the tree, leading to sparse growth,’ Jane reveals.

Other issues, which could make your olive tree look and feel sparser than it should be, is if pests or diseases start to ravage it and in extreme temperatures. You will need to protect your olive tree in winter as this can stress and damage the tree, leading to sparse growth. Be careful not to plant it too close to other trees or plants, as well, as this can result in water, nutrients and light being sapped from the tree, making it more of a struggle for it to grow fully.

Simply ‘by adjusting your pruning methods, you can make sure enough water and light reaches the centre of the tree,’ Georgina affirms.

How do you prune a potted olive tree?

‘Olive trees in pots are pruned the same as those in the ground, but they have a few special considerations,’ Jane admits. Much like ground planted olive trees, ‘potted olive trees need to be pruned in the early spring, just before new growth starts.’

You will want to keep an eye on its overall growth, however. ‘If the tree grows too tall for its pot, prune the top growth to keep it manageable but don't remove more than 20-30% of the tree's foliage in one pruning session,’ Jane warns. And after pruning your olive tree, you may want to repot it into a larger container to give it more space to grow.