Knowing exactly when to prune a plant is one of the most rewarding aspects of gardening. By learning the exact needs of each plant, gardeners can develop a sixth sense for the best time to prune each plant, resulting in vibrant foliage and beautiful flowers.
But it can be tricky to get right. Each plant has a different ideal pruning season. Even within the same group of plants, individual species can prefer slightly different pruning times.
This article will cover the ideal pruning seasons for several common types of plants, giving gardeners a good idea of when it’s time to prune.
What is pruning?
Pruning is a common task for virtually any gardener. By pruning plants at varying times, gardeners can encourage fresh bounties of growth for the next growing season.
Pruning also allows horticulturalists to remove any dead or sickly parts of a plant. This allows the flower or shrub to redistribute its energy to new growths, resulting in bushier and healthier foliage. By pruning crops such as fruit trees, growers can position the plant to produce a bumper yield the following season.
Some gardeners will also use pruning to shape plants like hedges or trees to create an ornamental plant in the garden.
When to prune your plants
Each type of plant has certain conditions that allow it to thrive during its growing season. Pruning is a way for gardeners to put plants in the best condition to grow healthily and happily. In this section, we’ll go through each season and detail what types of plants to prune and why.
Plants to prune in spring
Evergreens – Spring is one of the two times of year suitable for trimming evergreens. These trees don’t require drastic pruning but can be shaped at this time of year.
Fruit bushes & trees – An overlap between late winter and early spring is the ideal time to prune and trim fruit bushes (blackberry, raspberry) and trees (apple, cherry, pear). This helps to thin out and remove branches that won’t bear fruit ready for the new season.
Perennials – Early spring is one of the best times to trim away dead growth on perennials such as peonies and salvia. This helps them get ready for the new growing season.
Roses – Roses can either be cut back heavily in early spring if overgrown or pruned after blooming in late spring.
Summer flowering shrubs & trees – Shrubs and trees that flower in the summer, such as buddleia or myrtle, are best pruned twice a year, with one pruning coming in early spring. This shouldn’t be too drastic, but just enough to encourage fresh growth.
Spring flowering shrubs & trees – In late spring, once they’ve had their blooms, spring flowering plants can be pruned. This works best for plants that bloom early in the spring such as lilac or rhododendron.
Plants to prune in summer
Annuals – To get the most out of short-lived annuals such as begonias and dahlias, deadhead them throughout the summer growing season to encourage them to keep blooming.
Hedges – Summer is the ideal time to shape box hedges. Each time a hedge is trimmed, it should be allowed to grow a little higher before being trimmed again.
Hydrangeas – Midsummer is a good time to prune types of hydrangea that use their old woody stems to grow from. This helps to stimulate the newer buds.
Perennials – Perennials should be deadheaded throughout the summer growing season to help them produce more batches of blooms before the autumn.
Spring flowering shrubs & trees – There may be some overlap between the late spring and early summer for spring flowering plants. Once they’ve finished blooming, prune them to get them ready for next year.
Plants to prune in autumn
Fruit bushes – Most fruit bushes such as blackberries and raspberries begin to go dormant around October, which means that they can be pruned ready for the following year. This ideal pruning period overlaps with early spring. This long period is the time to remove old and dead growth.
Perennials – Autumn is the second time of year when perennials such as delphiniums can be heavily pruned down to the ground. At this point in the year, these plants are winding down and getting ready to go dormant over the winter. Pruning at this stage helps to promote renewed growth the following year.
Plants to prune in winter
Deciduous trees & shrubs – Like most plants, deciduous trees & shrubs go dormant in the winter. For many species such as dogwoods, maples, and oaks, this is one of the best times to prune old or unwanted growth. The plants will be able to conserve energy ready to start growing again next year.
Fruits bushes & trees – The ideal time to prune fruit bushes and trees overlaps between late winter and early spring. February is a good month to choose as pruning now helps stimulate the tree’s new shoots ready to grow a bumper fruit crop throughout the year.
Grapevines – Like other fruits, grapes go dormant in the winter. This is a good time to thin out old vines and heavily prune the plant to back near the lateral arms. This should encourage vigorous growth for the next year.
Tools to use when pruning
When pruning at any time of year, there are three main tools to use:
Hand shears/secateurs – These handheld clippers are good for most pruning applications, especially deadheading and trimming thinner stems.
Lopping shears – These two-handed shears have long handles, making it easy to reach stubborn stems. Lopping shears are also designed to cut through thicker stems and branches.
Pruning saw – For the thickest branches encountered while pruning shrubs and trees, pruning saws are ideal.
What cuts to make?
To get the best results from pruning, gardeners need to make the right kind of cuts. There are two main types of pruning cuts; heading and thinning.
Heading – Heading is mainly used during the growing season in the form of deadheading. This technique involves cutting off wilting blooms from annuals and perennials to encourage the plant to redirect its energy to newer shoots.
Heading is also used to help trees and shrubs to produce fresh new stems by cutting off the topmost part of the branch, freeing up newer buds further down the branch.
Thinning – Unlike heading, thinning takes a more drastic approach by pruning away an entire branch or stem. Thinning is mainly used to remove dead, diseased, or old branches and stems that would otherwise stunt the new growth of the plant.
Thinning is also used to thin out thick clusters of branches to let more sunlight into the plant and to reduce a plant’s overall size. This is the technique used when drastically cutting back perennials such as roses.
Summary
To summarise, getting the right pruning season mainly depends on which type of plant is being pruned. Some types of plants, such as annuals and perennials, can be lightly pruned throughout the growing season to encourage more flowering. Others, like fruit bushes, need old growth to be removed just before going dormant to help them produce a bigger crop next year.
