Fall weather has finally arrived! I haven’t had frost at our home, but I know it has hit most local areas already. We are all busy doing final tasks to put our gardens to bed for the winter. My priority this weekend will be to clean out the garden shed, rearranging all the items I store there so that the kayaks can be hung from the rafters for the winter. I am sure you have a to-do list as well!
I am still getting phone calls for advice about pruning shrubs before winter arrives. I do recommend that most pruning be done once the worst of the winter is over. In our area that is early spring, before new growth begins. Pruning in fall opens wounds that have no time to heal before winter sets in. Some trees and shrubs may experience tissue dieback at pruning sites.
Many people are asking how to prune the various types of hydrangeas they have in their gardens. I thought this would be a good time to re-share this information:
Annabelle hydrangea, (the variety with large, white, globe-shaped flowers), can be pruned quite hard. You can cut back as low as 12 inches from the ground. They bloom in July on new growth, so hard pruning in early spring encourages lots of potential for flower formation.
Their new cousins, the Hydrangea arborescens types with pink flowers (Invincebelle Spirit and Mini Mauvette), are pruned in the same way.
All the PeeGee types that have cone shaped flowers are pruned less dramatically. Just take off 1/3 to 1/2 of the newest growth, broken branches, and weak stems. This is now a huge family of plants including Limelight, Vanilla Strawberry, Bobo, Pinky Winky, Quick Fire and Fire Light.
If you are really set on pruning before winter comes, shrubs form either of these 2 groups can be done. However, any of the large leaf, fancier types with blue/pink flowers should be left alone until you see where new growth is emerging in spring. Many require old wood to be there next spring for growth to begin from as this is where blooms form later in the season. Once you see buds breaking, carefully remove the dead tips of branches above the new growth. Some examples of this group include Nikko Blue, Endless Summer, Summer Crush, Twist and Shout and all the Tuff Stuff varieties.
Most deciduous hedges are best left now and prune in early spring too. There can be exceptions. If you have a hedge that receives a heavy snow load in winter that causes damage and you know from experience that late fall is the best time to prune, just wait until at least mid November. You what temperatures to consistently be in the single digits Celsius before starting.
If you have a lilac hedge, prune it immediately after blooming. The flower buds for next season have already formed on the ends of the newest growth.
Evergreens are best pruned in late May or early June, after the first flush of new growth has finished. Pines are similar to lilacs, all the buds for new growth are at the ends of the branches. Pruning in fall or spring will damage them. Once your pine’s new growth looks like a candle, you can prune 1/3 to 1/2 of the candle length.
Cedar, hemlock, and yew can have straggly growth shortened a bit in spring but again, fallow the guidelines above for main pruning time. Evergreen hedges can be shaped again in late July.
Just remember, dead wood can be pruned away any time you see it. That holds true for broken branches as well. Always remove dead growth right down to base. Cut the broken branches down to the first set of healthy buds.
Sucker growth emerging at ground level from the base of an ornamental tree should be removed as soon as you notice it. Prune down as low as possible. You can pull soil away from the suckers and cut below the ground level.