Most of the leaves have fallen and it’s time to start thinking about fall chores. This usually presents a conundrum for most people; should I do it now or should I wait until the spring. Where possible, I prefer to leave most tasks until the spring. I still have quite a bit of planting to do, as well as putting the nursery to bed for the winter so the less I do now, the better.
When it comes to pruning trees, most trees should be pruned in the early spring. Of course, there are exceptions. Maples and birch trees have sap that runs freely in the early spring so you are better off to prune them now. Having said that, I prefer to prune Japanese maples in the late spring, after their leaves are completely out, just because they are a little more tender for us and if we have a hard winter, there will be less die back if you wait until late spring. I use the same logic with roses. A hard winter will cause the canes to die back a bit on the less hardy roses, like hybrid teas and floribundas. If you prune your roses heavily in the fall and then we get a hard winter, you’ll have even less to work with in the spring and can lose entire canes.
It is also a good idea to prune elms and oaks at this time. This lessens their chance of getting Dutch elm disease and oak wilt. Oak wilt is not yet a problem in Canada, but it is getting closer. It’s very much like Dutch elm disease in how it attacks the tree, but the beetles that carry the fungus need an open wound to pass it along so pruning when it’s too cold for the beetles is a good habit to get into. Similarly, ash trees should be pruned now to lessen the chances of emerald ash borers getting into the tree.
If you have any Viburnums, especially European snowballs (V. opulus), highbush cranberries (V. trilobum) or arrowwood (V. dentatum), now is a good time to look for Viburnum leaf beetle eggs. With the leaves off, they’re much easier to find. Look at this year’s growth; if you find a series of small raised bumps in a straight line, these are the eggs. Prune off the sections with the eggs and burn the infected stems. I used to do this in the spring, but with the increasing warm spells in the late winter and early spring, I’ve started making it a fall task.
I know that a lot of people like to cut back their perennials now so that their gardens are nice and neat come the spring, but I personally cut very little back in the fall. By leaving them up, you’re providing birds with food for the winter and nesting materials come spring. However, if you’ve had any powdery mildew or other fungus problems, cut those perennials to the ground now, collect the fallen leaves and burn them.