This is the first in a series of articles that can help you get the most from your landscaping while doing the least amount of work. Pruning is one of those chores that is often done for the wrong reason, or at the wrong time of year.
We are often asked questions like “is it too late to prune my ______?” or “do I have to prune this to keep it looking good?” or similar questions. First of all, no plant has to be pruned. We prune plants for several reasons:
- To maintain or reduce plant size (I don’t necessarily like this reason!)
- To remove undesirable growth, or direct growth in a desirable way
- To remove dead, broken, or diseased tissue
- To stimulate flowering or fruiting
- To rejuvenate or restore old, overgrown plants
- To prevent personal or property damage
- To shape plants into artificial forms
How and when we prune to accomplish these goals depends on the individual plant. Here are a couple of rules:
- Prune early flowering plants (lilac, rhododendron, viburnum, etc.) after flowering in the spring. This gives next season’s flower buds a chance to develop.
- Prune summer flowering plants in the dormant season or early spring
- When rejuvenating an old shrub, do it in thirds for 3 years
- DO NOT prune in late summer or early fall, as pruning stimulates new growth that will not harden off properly before winter (see photo of a fall pruned spirea in early summer with lots of dieback).
- Shade trees can be pruned dormant, or after the initial spring growth occurs. Oaks and elms should only be pruned during the dormant season to minimize the chance of disease.
As a plant guy, there are few things I find more unattractive than what could be a beautiful plant, pruned into an unnatural spheroid shape. Rather than pruning with hedge clippers, use a hand pruner to selectively remove longer growth. This will help control the size of the plant, but retain some of its natural beauty and shape. Better yet, select plants that are more suited to the size of the location. Good luck with all your gardening, and happy pruning (but not this fall)!
Here is a link to a good pruning primer from The University of Minnesota https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/pruning-trees-shrubs/