One of the main reasons that many people avoid summer pruning of trees and shrubs is a deep-seated fear of causing irreparable damage to these woody plants.
But while one should have a basic understanding of the science of summer pruning, there are 3 pruning cuts that can be tackled fairly easily by most gardeners pretty much anytime. It’s called 3D pruning.
3D pruning is simply the removal of stems and branches that fall, roughly, into 1 of 3 categories: Dead, Diseased, or Damaged.
Let’s look at each category:
Dead stems and branches don’t require any in-depth analysis! If they are dead they should be removed and the sooner the better. Dead branches provide plenty of "fuel" for a number of "plant pathogenes" or disease fungi that can attack healthy tree and shrub tissue.
Some stems and branches can harbour some serious diseases and still look quite healthy.
"Black Knot" is a good example. It is a devastating disease that attacks Mayday and Schubert Cherry trees and is easily recognized by black, lumpy-looking growths on a tree’s branches. Removal of the branches the moment the disease is evident is critical to minimize spread of the disease to uninfected branches.
Damaged branches and stems may be diseased, but often they are damaged due to other causes like winterkill, storm breakage, and insect pests. It’s best to remove damaged branches to allow your trees and shrubs to dedicate their precious resources to production of healthy tissue that can contribute to the overall vigour of your plants.
Summer Pruning Notes
Once you feel confident in tackling 3D pruning there are 3 more things to consider before starting:
- Use high-quality pruning tools and the right ones for the job. A razortooth pruning saw, secateurs, and loppers are the basics for pruning. Don't make the mistake of using a carpenter's saw as isn't designed for cutting trees—a razortooth pruning saw is what you need to properly cut the wood of your tree.
- Be aware that Elms cannot be pruned from April to October due to the risk of spreading Dutch Elm Disease. Elms, in our part of the world, can only be legally pruned November to March.
- Safety. Prune only those branches and stems that you can prune safely. Leave all other pruning for the pros!