Walnut Tree Pruning – Getting the Timing Right

Between mid-summer and early autumn.

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When is the best time to prune a walnut tree? Why prune a walnut tree? And what diseases and pests should you look out for during walnut tree pruning? Read on to find out…

The walnut tree, Juglans regia, is a tree that, although not native to the UK, has become popular throughout this country, particularly in parks and large estate gardens.

Walnut trees tend to grow to heights of 35 metres. They are distinguishable by their short trunk and broad crown, although they can look a bit different when growing in woodland. You’ll find the bark olive brown and smooth during the formative years, fading to silver-grey with age. Leaves are shiny and pinnate and give off a polish-like odour when crushed.

The wind-pollinated fruits start life as dark green husks developing into the well-known brown, wrinkled-looking nut – the walnut – a favourite of squirrels and mice.

Why prune a walnut tree?     

Walnut trees, given the space, will grow wide and tall with expansive canopies. If you want to restrict the size of the tree, perhaps because you are limited on space, then pruning to remove the central leader and therefore encouraging side shoot production is the best way to do this. Simply pinch off the side shoots at the fifth or sixth leaf which will promote bushing.

Aside from this, regular pruning isn’t generally required, other than to remove crossing or rubbing branches, or any that are forking in unruly directions. The aim here is to promote the good health and appearance of the tree. In addition, the removal of dead wood and damaged branches is essential to keep the tree safe.

When is the best time for walnut tree pruning?

Walnut trees are prone to sap bleeding so it is imperative that any pruning is undertaken between mid-summer and early autumn. Otherwise bugs will be attracted to the tree, which are likely to introduce diseases, putting the tree at risk.

Never hard prune a walnut tree: it will not tolerate it. It is vital that no more than 20 per cent of the crown is removed in any one pruning session.

What to look for when pruning a walnut tree

The walnut tree is susceptible to aphids and the walnut blister mite as well as coral spot and leaf spot.

In addition, grey squirrels can be particularly hazardous. Many people opt to wrap the tree in plastic guarding and lift the crown to up to 2.5 metres in order to deter attack.

The walnut leaf gall mite causes large yellow blisters to appear on the upper surface of the leaves. Walnut leaf blotch is a fungal disease that thrives in periods of wet weather. It mostly affects the leaves of the tree but can also attach young shoots and fruits. Thankfully mature trees are rarely affected although fruit crops can be destroyed. The codling moth can also cause damage to the nuts of the tree.

Tree Preservation Orders

Any tree work you need to undertake should be cross referenced with the local authority to check whether there is a Tree Preservation Order (TPO) in operation. Where there is, you will need to apply for permission to carry out works and this may take up to eight weeks to come through. In addition, if the tree is located in a conservation area, you will require permission before undertaking works of any kind.

The importance of walnut tree pruning expertise

If you are keen to make sure your walnut tree is cared for in the best way possible then your best course of action is to engage the assistance of a qualified and experienced tree surgeon.

Tree surgeons are subject to in-depth training and are therefore aware of how to undertake walnut tree pruning using the correct methods at the right time of year. They also know very well how to identify diseases and pest infestations and resolve them successfully in order to keep the tree in perfect health.

When engaging a tree surgeon, make sure you demand evidence of checkable references and certificates for reassurance that they actually hold the qualifications they say they do. Also ask to see their insurance documents so you know you are covered for the work being undertaken,

Wherever possible, look for Trading Standards and local authority approval so that you know you’ll be getting the best possible quality and value for money.

If you have a walnut tree that requires professional pruning, why not contact T.H. Tree Services? As fully qualified and highly experienced Trading Standards and local authority approved tree surgeons, we can offer specialist expertise in all aspects of walnut tree pruning. For a free, no-obligation quotation, contact our helpful experts on 01268 642814 or get in touch here.