How to Prune Walnut Trees

Proper pruning of walnut trees is very important for establishing strong tree structure, promoting fast growth, and bringing the orchard into production as quickly as possible. According to recent research, minimal pruning approach gives the best results. In this article, we will guide you on how to prune walnut trees using the minimal/no pruning approach, following the best practices.

At Planting:

When you are planting your new young walnut trees, your first instinct might be to plant them as they are, without losing any centimeter of them. However, you need to prune them a bit in order to make sure that they grow in a healthy way. When a tree is dug up from the soil at the nursery, it inevitably loses some of its root system. Pruning the tree a bit from the top compensates for this loss, and establishes a balance between roots and the body. Here is how you should prune your trees after you planted them.

Look at the grafting point of the tree
Count 4-6 buds above this point (or you can measure 60cm above the ground)
Make an angled cut at this location

This initial pruning may seem like you are losing some growth of the tree. But it's a proven technique to help establish healthy walnut trees and maximizing their chances of success.

First Growing Season:

First growing season is the first summer of the trees. Let's say you planted the trees in March 2025, the first growing season starts in June 2025. The primary goal for this season is to establish a strong central leader.

Key actions:

Allow the tree to grow freely, promoting vigorous vertical growth.
Remove any branches emerging from the trunk below about 4 feet. This provides necessary clearance for future shaker attachment during harvest operations.
Monitor for and remove any suckers emerging from the rootstock.
Ensure proper irrigation and fertilization to support strong growth.

First Dormant Season:

This is the first winter after you planted the trees. For example, let's say you planted the trees in March 2025. The first dormant season starts in November 2025. Or to explain in a different way, once you plant the trees and their first summer is over. When the tree sheds its leaves after summer and goes dormant (winter sleep) it is their first dormant season.

When this season starts, the trees are pruned to establish a central leader system. The central leader branch needs to be a strong branch growing from the trunk. You can choose it by following the instructions below:

Vertical growth: Look for the most upright, vertical branch growing from the main trunk. The central leader should be growing straight up or nearly so.
Vigor: The central leader should be the most vigorous shoot on the tree. It will typically be thicker and longer than other branches.
Position: Ideally, the central leader will be centrally located on the tree, emerging from the top of the trunk.
Bud arrangement: The central leader should have a strong terminal (top) bud and well-spaced lateral buds along its length.
Angle: While other branches should have wider angles (ideally 45-60 degrees from the trunk), the central leader should have a very narrow angle, almost vertical.
Dominance: The central leader should be noticeably taller than other branches on the tree.
Straightness: Look for a straight branch without significant bends or kinks.
Health: The central leader should be free from damage or disease and have healthy, vibrant leaves.

If multiple branches are competing to be the central leader, choose the one that best fits the criteria above. If two branches on the tree are very similar, you can choose the one that looks stronger based on your gut feeling.

Once you have chosen a branch to become the central leader, remove all other branches from the trunk, focusing growth into the central leader. Also, eliminate any "neck buds" at the base of the trunk. These produce weakly attached branches prone to breakage and can interfere with future shaking operations.

Second Growing Season:

Second growing season is the second summer of the tree, starting in June. During the second growing season, the focus remains on promoting strong growth and maintaining the central leader system.

Key actions:

Allow the tree to grow freely, continuing to focus energy into the central leader.
Remove any suckers or low branches that emerge from below the graft.

Second Dormant Season:

Key actions:

Remove any forks with branch angles less than 20 degrees from vertical on the trunk.
Remove any remaining growth below 4 feet on the trunk.
No other cuts are made, allowing the tree to develop its natural structure.

Other Years

Only prune as needed to allow orchard access and remove dead or diseased branches.
Monitor for and remove any branches that could interfere with shaking or other orchard operations.

Conclusion

At Waltree Nursery, we are always following developments in the sphere of nut trees, and reading the research papers published by leading universities. Our approach to pruning is based on the recent studies done in the past few years. In this guide, which is based on the latest research, we have covered how you can maintain your walnut orchard with minimum or no-pruning approach.

In the past, it was believed that every year, lots of pruning needs to be done with complicated steps and technique. However, recent studies with walnut trees show that when they grow naturally with minimum pruning and intervention, they show the same performance. By allowing trees to develop their natural structure with minimal intervention, you can establish healthy, productive walnut orchards while reducing labor costs and getting better yields.