There are two types of heading cuts.
Selective heading is where the cut is made selectively just above a side branch or bud. When pruned just above a side branch, normally one branch regrows for each one removed, keeping a plant about the same thickness.
Nonselective pruning is when cuts are made without regard to side branches or buds. Shearing produces nonselective cuts. The typical regrowth from nonselective pruning is three or more branches from each one removed. After shearing three times, regrowth can be 20 to 30 times as thick as the original. The plant loses its natural thickness and shape.
With natural pruning, most cuts are made just above a side branch. If growth is thicker than desired, some thinning cuts are made, removing whole branches. Upper branches need to be pruned shorter than lower ones. When lower branches become shaded by longer upper branches, they gradually lose their leaves and the shrub develops a “chicken leg” appearance.
I like to start at the bottom, pruning the lowest branches a limited amount to establish the width of a shrub. Then I prune the next level of branches so they are a little shorter than the ones below. I like to make cuts a little inside surrounding growth so the cut ends are covered by adjacent smaller growth.
The best book on pruning I have found is “Guide to Pruning” by Cass Turnbull. Used copies of this book are available for as little as $5 on line. Although she does not call it natural pruning, the first chapter of this book is an excellent detailed description with illustrations of natural pruning as I practice it.
Allen Wilson is a Vancouver gardening specialist. allenw98663@yahoo.com
