High-Pruning Walnut Trees

Now is the best time of year to prune walnut trees. Enjoy a short video of me at work, high-pruning some young black walnut I planted as a young forester.

I recently had the pleasure of meeting up with a longstanding research colleague and fellow silvologist Prof J P Skovsgaard from Denmark. We were together in a young plantation measuring some promising young wild service (Sorbus torminalis) as part of a research trial, but given my interest in walnut silviculture, my eye was drawn to some black walnut (Juglans nigra) trees that I planted back in 1995.

Sadly, the walnuts had never been pruned, but luckily I had my 4m-long silky pruning saw in my back pocket. Well, figuratively at least, to hand.

It took just three minutes to prune the lower 50% of the tree of its small branches. The result was a clean stem of about 6m in length. From now on, every annual increment of growth on that stem will be free of branches, producing ‘clean’ timber. The previous year’s growth, when the branches were still in place, will have resulted in knots, but these will be limited now to the centre of the tree, the so-called ‘knotty core’. That means from every year now on, the tree will be fulfilling its promise as a veneer-grade walnut tree.

“Three minutes to turn a reject tree into a prime specimen. Not a bad investment of time over 45-50 years.”

Gabriel Hemery

Walnut trees, like cherry, are best pruned in the summer. Tradition in the UK suggests that St Swithin’s day (15th July) is the best time of the year. Read more about pruning walnut trees