Fall is a favourite time for clean-up in the garden. We clear out all of our tired and spent annuals, remove leaf litter from the beds and patch our lawns. While we’re in the throes of our clean-up, it’s awfully tempting to get out the pruners and cut back our trees and shrubs to finish everything in one fell swoop. But…
Though it goes against popular opinion, our nursery staff strongly object to this practice.
When it comes to trees and shrubs, we cannot stress this enough: Fall is a Pruning-Free Season!
There are a number of reasons why we caution against it.
- In the fall, plants devote much of their energy downward – they’re gathering energy in their root mass so they’re able to push out new growth next spring. This means your plants are less likely to quickly repair the pruning cuts you make, which can lead to an assortment of pest and disease problems down the road.
- Some insects exploit fall pruning cuts as they search for a place to hide for the winter.
- In some situations, pruning will encourage sap to travel up the plant and encourage new growth. We don’t want this happening in the fall. Trees and shrubs need to wind down in the fall, not push out new tender branches. Tender growth will be quickly killed by cold temperatures, and as a double-whammy, your plant’s energy reserves will be depleted after expending so much, leading to weak growth next year.
- Hard winters cause dieback on many of our plants. It’s much easier to prune next year once evidence of such damage becomes clear. Otherwise, you may end up pruning twice – once in the fall, and once next season when you’re faced with dead branches. Save yourself the headache and skip the fall prune.
If fall pruning is such a bad idea, why do many gardening resources encourage it? A quick search will reveal many websites and gardening resources that advocate fall pruning. There are a few considerations to make in this regard:
- Ensure the resource is specific to Southern Ontario. In warmer or otherwise different climates, shrubs may flower at different times, winter damage may not be as great an issue, different pests and diseases may be more or less prevalent. This may make fall pruning possible.
- Ensure the resource is specific to the shrub or tree you wish to prune. Every plant has different needs and growing habits. It’s tempting to prune several different plants uniformly because it’s faster and more efficient, but you might be doing your plants a disservice. A resource advocating the fall pruning of one plant does not mean fall pruning is suitable for all plants.
- Ensure the resource is credible. Sifting through message boards and gardening forums is invaluable in troubleshooting and for getting the scoop on unusual plants. However, information shared is sometimes highly anecdotal and may not apply to your situation. A frequent poster might advocate fall pruning, but that doesn’t make it true.
A final thought: we don’t want to sound alarmist. Pruning in the fall will not suddenly kill all of your plants. However, it is still a bad idea, and there is always a better time to do it. So, put those pruners away!
For more information on pruning practices, consult our tip sheet Pruning Trees & Shrubs: Why When?