Why do you prune plants in the garden? The most straightforward answer is to encourage plants to grow properly in the space they are provided, so that they have a nice form and flower well or produce nice fruit, if they are flowering plants. Pruning also removes dead, diseased or damaged portions of shrubs, trees and hedges. This results in stronger, healthier more vigorous plants.
When to Prune Shrubs, Fruit Trees and Vines
Plants that need to be pruned in spring, before flowering.
Hibiscus syriacus ‘Diana’
The following plants flower on new wood, or branches that grow during the current growing season. The plant can be cut back before growing starts in the spring.
- Abelia
- Barberry (Berberis)
- Bluebeard (Caryopteris)
- Butterfly bush (Buddleja)
- Clematis (late-flowering group)
- Heath & Heather (Calluna and Erica)
- Fuchsia (hardy varieties)
- Rose of Sharon (Hibiscus)
- Honeysuckle (Lonicera)
- Lavender (can also be cut back in fall in Vancouver because of our milder climate)
- Mallow (Malva) Can be cut back by half in May to make Mallow more compact and bushy.
- Shrubby cinquefoil (Potentilla)
- Red-twig dogwood (Cornus)
- Roses (can be done as early as January in Vancouver)
- Sage (Salvia)
Plants to prune after flowering.
Escallonia Newport Dwarf
These are plants that bloom on old wood, so be sure to prune right after flowering is finished to allow plants more time during the growing season to push out the branches for next year’s flowers.
- Cherry (Prunus)
- Clematis (early flowering species)
- Escallonia
- Forsythia
- Hydrangea (some new varieties such as the Endless Summer and Blushing Bride series bloom on both old and new wood, so save the pruning until fall)
- Japanese flowering quince (Chaenomeles)
- Mock orange (Philadephus)
- Plums
- Roses (ramblers and shrubs) Deadhead flowers back to the first set of true leaves, that is those leaves containing seven leaflets on them.
- Spirea
- Viburnum
- Weigela
- Wisteria
Pruning Principles and Tips
Begin by pruning out dead, diseased or damaged material from your plants. This is known as the 3-D’s of pruning. Oftentimes, this is all that needs to be done to improve your plant material. After you have done your 3-D pruning, take a look at the plant.
You can then prune any branches that cross over another branch, causing rubbing or weighing down the other branch. Cut out branches that are too big, or spindly and weak looking. You can also remove branches that are downright ugly! Remember that you are trying to achieve an overall symmetry and even form for the plant in most cases.
Cut back one third of the stems right down to the ground. Removing the oldest, thickest stems – this is especially true for roses – will help generate vigorous new growth. The remaining stems can be cut back by a third of their height.
This pruning work will help keep your plants young and healthy, providing you with beautiful blooms throughout the growing season.