Fall is the ideal time to prepare some of your plants for a spectacular bloom the following spring. A well-executed pruning stimulates growth, improves the health of the plant, and prevents damage. Here is a guide to help you prune your plants with confidence.
When to Prune in the Fall?
The best time to prune is after the leaves have fallen but before the first frost. In Quebec, this generally corresponds to the period from **late September to late October**. It is essential that the weather is cool but not yet freezing, so as not to stress the plant and to avoid stimulating new growth before the frost.
Summer or Fall-Blooming Shrubs
You can safely prune shrubs that bloom on the new wood of the year in the fall. By pruning them now, you stimulate their flowering for the next season.
- Panicle Hydrangea (Hydrangea paniculata): Prune it by removing faded flowers and cutting branches back by half or two-thirds of their length. This will encourage large flowers next year.
- Spireas and Potentillas: Cut them back by half.
- Butterfly Bush (Buddleia): Prune it to 15-20 cm (6-8 in.) from the ground.
Evergreen Shrubs
For shrubs that keep their foliage in winter, such as boxwoods or hollies, a light pruning can be done in the fall. The goal is to maintain their shape and remove dead or damaged wood. More significant pruning should be done in the spring.
- Boxwood and Holly: You can perform a light pruning to maintain their shape and remove dead or damaged branches.
- Evergreen Conifers: Wait until spring; fall pruning can weaken them.
Fruit Trees and Roses
The main pruning of these plants is done in the spring, but a light pruning in the fall is essential for the plant's health.
- Roses: Lightly prune the rosebush to about 50 cm (20 in.) from the ground to prevent wind and snow from breaking the branches. This pruning also facilitates the installation of winter protections. Clean the base to remove leaves and faded flowers to prevent diseases.
- Fruit Trees: Do not perform any major pruning. Simply remove dead or damaged branches, as well as any remaining fruits on the branches (mummified fruits), to prevent the spread of diseases and the proliferation of insects.
The Golden Rules for Proper Pruning
For successful maintenance, it is essential to follow a few good practices for clean and efficient pruning.
- Use clean, sharp tools for clean cuts.
- Cut just above a bud or a lateral branch.
- Systematically remove damaged branches, dead wood, and entangled branches.
- Limit pruning to 20-30% of the plant's canopy per year.
Plants Not to Prune in the Fall
To avoid compromising the bloom or weakening your plants before winter, it is crucial to wait until spring or summer to prune them.
- Spring-Blooming Shrubs: Do not prune forsythias, magnolias, lilacs, and others that bloom on the previous year's wood.
- Trees Prone to Bleeding: Avoid pruning maples, birches, and walnuts, as this would cause a significant loss of sap.
- Conifers: Wait until spring; fall pruning can weaken them.
By following these rational pruning tips, you contribute significantly to the health and aesthetics of your garden. Proper maintenance is the best way to ensure a lasting bloom throughout the seasons.
