How to prune magnolia trees

The sight of a magnolia in full bloom is one of the highlights of the gardening year. They make beautiful specimen trees and some, like the evergreen Magnolia grandiflora, can be trained against a wall.

Unless they’re being trained, magnolias don’t need regular pruning. In fact, it’s best to avoid pruning established trees unless absolutely necessary. If you do need to limit the size of your tree, here are our top tips for pruning magnolias. 

When to prune a magnolia tree

This compact deciduous variety often produces a second flowering in mid-summer
Image: Magnolia 'Genie' from Thompson & Morgan

When and how to prune your magnolia depends on whether it's deciduous or evergreen. Deciduous varieties should be pruned in late summer, evergreen varieties should be pruned in spring, and wall-trained specimens should be pruned in summer after they have finished flowering.

Many magnolia varieties bleed when cut, so it’s important to prune at the correct time of year to avoid this. Make sure you have a sturdy step ladder, a pruning saw and sharp secateurs.

How to prune deciduous magnolias

Prune deciduous magnolias from mid- to late summer to prevent the cuts from bleeding
Image: Magnolia 'George Henry Kern' from Thompson & Morgan

• When deciduous magnolias are young, prune out any weak growth or branches that spoil the overall shape.
• In subsequent years, only prune to remove dead and damaged wood, or to improve the shape.
• Mature trees often produce vertical shoots, known as watershoots. These should be removed by cutting back to the trunk or branch.
• Always prune between mid-summer and early autumn when the leaves are fully open.
• If you need to limit the size of your magnolia, aim to maintain an open crown with a uniform shape. It's better to cut back to a fork or the trunk, which gives a better appearance.
• Carrying out renovation work over several years will avoid putting undue stress on the tree.

How to prune evergreen magnolias

Evergreen magnolias should be pruned as little as possible
Image: Magnolia grandiflora 'Alta' from Thompson & Morgan

• Young, evergreen magnolias generally don't need pruning, unless you wish to remove lower branches to create a clear trunk.
• Once established, prune to remove any damaged growth or to maintain shape, if needed.
• Pruning evergreen magnolias should always be done in spring, as growth starts.

How to prune wall-trained magnolias

Wall-trained magnolias should be pruned in summer
Image: Debu55y/Shutterstock

• Wall-trained magnolias are pruned in summer - doing it after flowering means there's less chance of removing flower buds by accident.
• Any stems that are heading towards the wall should be removed. Those that are growing away from the wall should be shortened to one or two leaves.

We hope these pruning tips will help you to enjoy a strong and healthy magnolia tree for many years to come.