Olive trees are beautiful Mediterranean trees that can look wonderful in a sheltered, warm spot here in the UK, but learning how to prune them correctly is important.
When and how to prune your olive tree and the reasons for doing so, will vary depending on why you are growing your olive tree, where you are growing it and what precisely you are aiming to achieve.
Olive trees can be beautiful trees to grow in a warm, Mediterranean style garden. But understanding how to care for your olive tree correctly is important and that includes understanding how and when to prune the tree.
In this article, we will look at some of the things you need to think about when pruning an olive tree, so that you have a better idea of how to care for one growing in your garden.
When to Prune Olive Trees
First of all, whenever pruning an olive tree (for whatever purpose and with whatever goal) it is important to choose the right time for the job.
Typically, you will prune an olive tree between late spring and the end of summer.
It is important not to prune your olive during the winter, as this can make the tree more vulnerable to infection with disease. Always prune over the warmer part of the year to reduce the chances of disease taking hold.
Unfortunately, olive trees can be rather prone to a number of diseases, especially in a cooler climate. And pruning incorrectly and at the wrong times can make it more likely that one will take hold.
Some only slightly impact the appearance of the tree, but some diseases could actually kill your olive tree outright.
Do You Need To Prune Olive Trees?
Though pruning can often be a good idea, olive trees are relatively slow-growing and should not need a lot of pruning at all in most scenarios. However, it is important to note that it is good practice (with an ornamental olive tree) to remove any dead, damaged or diseased materials as part of general care and maintenance.
If you are trying to grow an olive for its fruits, then the pruning considerations are somewhat different. It is also important to understand that this is not very easy in the UK, as the trees will typically only fruit in the mildest and warmest of UK gardens.
And even when the fruits do set successfully, you will still have to harvest the fruits before the first frosts and cure them before they are used. Curing is essential if you want olives that taste like those you can buy in the shops.
Bear in mind that these trees thrive in the hot, long growing season of the Mediterranean and so work will be required to obtain an edible yield in our climate, with our much shorter growing season.
Another consideration is that here in the UK, olive trees are often grown in containers, and some pruning may be required for container-grown trees to keep their size in check and to stop them from outgrowing a container.
In short, therefore, you might wish to prune olive trees:
- For simple maintenance.
- To encourage fruiting and promote new fruit production.
- To keep the size and shape of the tree in check.
However, while olive trees can respond well to pruning, it is important not to go overboard. Prune too excessively and the tree may put forth numerous water shoots (not fruiting growth).
This is not ideal if you are trying to produce fruit, of course. It can also detrimentally affect the overall appearance of your olive tree. Olives should usually be pruned quite lightly in order to preserve a more natural appearance.
Maintenance Pruning on Olive Trees
Usually, if an olive tree is growing in the ground, light, maintenance pruning is all that will be required.
Simply remove any branches which are causing damage by rubbing on one another, and any which have been damaged over the winter months in late spring or early summer.
At the same time, you may also prune some branches at the centre of the canopy to let more light in to new growth, and remove a side branch or two to maintain a pleasing shape.
But do not overdo it – less is usually more when it comes to maintenance pruning on an olive tree that is grown for ornamental reasons and not for its fruit.
Pruning For Fruit
When pruning an olive tree for fruit, one of the most important things to remember is that olives fruit only at the tips of the previous year’s growth. Pruning too zealously can prevent fruiting.
However, not pruning at all can lead, over time, to a tree with too much older wood, which may also restrict new growth and prevent light from reaching and ripening any fruits that do form on the last year’s branches.
It is a good idea, therefore, to prune out sections of old wood each year to allow some newer fruiting growth to form.
It is also recommended to thin fruits that form to no more than 3-4 for each 30cm of branch. This should help ensure that the olives ripen successfully and will not drop off the tree prematurely before harvesting time.
Pruning to Restrict Size and Preserve Form
Pruning to restrict size is not usually a concern when these slow-growing trees are grown in the ground. But when they are grown in containers, you may need to do some additional pruning so they do not outgrow their pot.
In addition to the general maintenance pruning in the late spring or early summer, a container-grown olive may also require additional pruning in summer to restrict their size.
If you are not bothered about fruit production, you can reduce the canopy size of your tree by up to 1/3 to keep its size in check.
When olive trees in containers grown to around 1.5m tall, it is also often a good idea to prune to preserve or create a pleasing form.
Choose a few of the strongest and best-placed branches and keep these, but get rid of other shoots. You might also pinch out the growing tips to encourage branching and a bushier canopy.
Olive trees are not the easiest trees to care for and grow successfully in a UK garden. But pruning them is rarely a hugely complex business.
It should also be noted that you can take pruned branches in summer and use these as semi-ripe cuttings to propagate new olive trees from the parent plant.
A permaculture garden designer, sustainability consultant and freelance writer, Elizabeth works as an advocate for positive change. She aims to inspire others to reconnect with nature and live in a more eco-friendly way. She also tries to practice what she preaches as she tends her own forest garden, polyculture beds and polytunnel. See her personal website here.