Now that it’s starting to feel like fall again, many of us are resuming our outdoor work. In addition to cutting the grass, getting flower beds cleaned up and raking leaves, make sure to give your trees and shrubs some attention too.
The last few months have been rather dry, and many of our trees and shrubs that haven’t received irrigation are likely suffering from drought stress. To help prepare trees for the coming winter they should be watered until the ground freezes. Watering trees and shrubs before they go dormant will help reduce their stress. This is especially important for evergreens. Because evergreens keep their leaves year round they are more likely to suffer winter desiccation (also known as winter burn). Desiccation is caused when plants lose moisture faster than they can take it up. This will result in discolored and damaged plant leaves and tip dieback. Having well-watered trees and shrubs and adequate soil moisture can go a long way in preventing winter desiccation.
Mulching trees and shrubs is also beneficial when preparing them for winter. Mulch will help retain soil moisture and help prevent soil temperature fluctuations. Organic-based mulches, such as wood chips, are preferred because in addition to the above benefits they will also slowly break down and add nutrients to the soil. When applying mulch put down a 2 to 4 inch deep layer, ideally out to the drip line of the tree. There should be a 2-inch gap between the tree trunk and the mulch; the mulch around the tree should look like a donut, not a volcano. Mulch piled up against a tree trunk creates an ideal environment for diseases and insects.
When it comes to pruning trees and shrubs it’s best to hold off this time of year. Pruning trees in late summer and fall can encourage new growth. This new growth won’t have time to harden-off (acclimate themselves to winter conditions of colder temperatures and shorter days) before winter arrives, resulting in it dying. The only pruning that should be done is to remove dead or damaged branches. Wait to do any other pruning, such as removing crossing and rubbing branches, until the trees are fully dormant (late winter is a good time).