Here are some tips on when to prune shrubs and trees, as well as flowers, for healthier plants
Pruning many trees, shrubs, or perennials at the right times of the year can result in more blooms and stronger growth. The type of plant will prune shrubs and trees determine the best time to prune it. This guide takes the mystery out of pruning your plants.
Getting Started
It is important to remove any dead, diseased, or damaged branches as soon as possible. Dead stems can attract insects and encourage disease to grow. Take out any crossing branches, water sprigs (vigorous upright-growing shoots) and suckers. These are vigorous shoots that can grow near or below the ground.
When to prune Hydrangeas
Many hydrangea species can thrive on old wood. This is a good time to prune hydrangeas that aren’t in season. Pruning them in winter or early Spring will result in the removal of flower buds.
For reblooming types like the Endless Summer Series (or Let’s Dance Series), it’s less important to prune because these hydrangeas will bloom on both new and old growth. Even if you remove some flower buds from the old stems, they will still blossom on the new growth.
White-flowered paniculata, which is similar to the varieties ‘PeeGee” and ’Limelight’, and arborescens type flowers on newwood so they can also be pruned anytime other than just before blooming.
Shrubs and Trees that Bloom in Spring
Early-spring flowerers such as lilac, forsythia and rhododendron will produce flowers from wood from the previous year. It is best to prune them in late spring, right after the flowers have finished blooming. Pruning them later in the year or during winter will result in flower buds being removed and a decrease of spring bloom.
- Tip for Spring Bloomers: Take out any older shoots as far as the ground. This allows for younger stems and more bloom.
Shrubs and Trees that Bloom in Summer
Crape myrtle and potentilla are two examples of plants that flower in summer. Their flowers are produced from new growth during the current season. They can be pruned in winter, when they are dormant, and in spring, just before the new growth emerges. Even if you cut them to the ground in the winter, they will still flower the next summer.
- Tip for a Test Garden: A pole pruner with a rotating heads can be used to remove stems up to the base. You don’t need to bend over each time you make a cut. This not only saves you time but also your back.
Shrubs with No Showy Blooms
You can cut back deciduous shrubs, which are usually grown for their foliage (like the golden smoke tree), at any time, except late autumn. If you prune in the late season, new growth will not survive winter. You should prune your shrubs when the weather is cool.
When to trim clipped hedges
To maintain the shape and size of shrubs such as boxwood, you should shear new growth often during the first part of the growing season. To ensure the upper branches don’t shade the lower ones, keep the top slightly narrower than that of the base. You should stop shearing your hedge six weeks before the average first freeze in your region. You can prune hedges more aggressively in the late winter, early spring, and mid- or late summer.
- Test Garden Tip To reduce pruning, choose shrubs that only grow as high and wide as is necessary to screen out the view. If you allow them to grow in their natural state, you won’t need too many prunings.
When to Prune Roses
Old garden roses and climbing roses that bloom once per year are treated the same as all other spring-blooming shrubs. After they stop blooming, prune them. Hybrid teas, floribundas and grandifloras as well as miniatures and modern roses can be repeated bloomers. They are pruned mainly to shape the plant, or to remove winter damaged stems (as seen here). Cut them back in spring if they are too tall.
When to prune Deciduous Shade Trees
When they are dormant in the winter, prune shade trees like oak, Linden, and Ash. It is easier to see the branching structure during this time of the year and it is less likely that you will spread diseases through the pruning wounds. Don’t prune them too late in the season, as with other non-blooming shrubs.
- Test Garden Tip Trees producing a lot of sap when they are pruned in winter –maples, birches and elms–are called “bleeders”. While the sap flow is not visible, it doesn’t cause damage to the tree. You can avoid bleeding by waiting until the leaves are fully expanded in the summer before you prune these species.
When to prune deciduous fruit tree trees
Midwinter is the best time to prune apples, including crabapples, peaches, pears and plums. While winter pruning can remove some of the blossom buds, the goal is to open up fruit trees to allow more light in order to produce better fruit. Crabapples, apples, and pears are especially impacted by fireblight.
- Test Garden Tip Dip your pruning shears into rubbing alcohol, or a solution of one percent bleach to nine percent water, in order to control disease spread.
When to prune Broadleaf Evergreens
The majority of broadleaf evergreens (holly, mahonia, some magnolias) don’t need to be pruned. In the early spring, before their growth spurts begin, is when it’s best to prune them. Other times of the year are also suitable for minor shaping and pruning.
- Christmas Tip: You can save on holiday decorations by cutting a few branches.
