A Guide to Pruning UK Flowers and Shrubs
Pruning is one of the most important tasks in a gardener's calendar. It might seem daunting at first, but with a little knowledge, it becomes a rewarding practice that ensures your plants are healthy, productive, and beautiful. This guide will walk you through the fundamentals of pruning, from the reasons why we do it to specific techniques for common plants.
Why We Prune
Pruning is a plant management technique that involves the selective removal of parts of a plant, such as branches, buds, or roots. The primary goals of pruning are:
To Maintain Health and Vigor: Removing dead, diseased, or damaged branches prevents the spread of infection and allows the plant to direct its energy towards healthy growth.
To Control Size and Shape: Pruning helps keep plants from outgrowing their space and allows you to create specific forms, such as a neat hedge or a tree with a clear trunk.
To Encourage Flowering and Fruiting: Many flowering shrubs and fruit trees bloom best on new wood. Pruning encourages the growth of new stems, leading to a more abundant display of flowers or a larger fruit harvest.
To Improve Air Circulation: Removing crowded or crossing branches opens up the plant's canopy, allowing for better airflow. This reduces the risk of fungal diseases.
When to Prune
The timing of pruning is crucial and is almost always based on when a plant flowers. A general rule of thumb is:
Prune Spring-Flowering Plants after they have Flowered: These plants, like Forsythia and Lilac, produce their flowers on last year's growth. Pruning them in late spring or early summer after the blossoms fade ensures you don't remove next year's flower buds.
Prune Summer-Flowering Plants in Late Winter or Early Spring: These plants, like Roses and Hydrangeas, produce flowers on new growth. Pruning them before they start to grow in spring will stimulate new shoots and a great summer display.
Essential Pruning Techniques
1. The Three D's: Always begin by removing any branches that are Dead, Diseased, or Damaged. Cut back to healthy wood, making the cut just above a healthy bud or branch junction.
2. The 45-Degree Angle Cut: When making a cut, angle it slightly so that rainwater runs off the cut surface, which helps prevent disease. Make the cut just above a bud or a branch, leaving a small "collar" of bark to aid healing.
3. Thinning and Renewal Pruning:
Thinning: This involves removing entire branches or stems at their base to open up the plant's centre and improve air circulation.
Renewal Pruning: Used for older, congested shrubs, this technique involves cutting back one-third of the oldest stems to the ground each year over three years. This encourages vigorous new growth from the base.
Pruning Guide for Top UK Flowers and Shrubs
Here is a quick guide for some popular garden plants:
Roses (Rosa species):
When: Late winter or early spring (for bush and climbing roses).
How: Remove the three D's. Then, cut back the main stems by one-third, cutting to an outward-facing bud to encourage a good shape. Deadhead throughout the season to promote more blooms.
Hydrangeas (Hydrangea species):
When: Late winter or early spring.
How: Remove dead flowers and any weak or twiggy growth. Cut back the main stems to a pair of strong buds.
Lavender (Lavandula species):
When: After flowering, in late summer or early autumn.
How: Trim off all the spent flower stems and around an inch or two of the foliage. Avoid cutting into the old, woody base of the plant, as it may not regrow from there.
Japanese Maple (Acer palmatum):
When: Late summer or early autumn (when the sap is not running).
How: Only prune to remove dead or damaged branches. Be very careful with pruning, as it can ruin the graceful shape.
Buddleia (Buddleja davidii):
When: Early spring.
How: This shrub blooms on new wood, so it can be pruned hard. Cut back all the stems to a strong framework, leaving a few buds on each stem, to encourage lots of new growth and a profusion of flowers.