Pruning your trees, bushes, and perennials is a great way to keep them healthy and promote active new growth. However, it’s easy to cause more harm than good to your bushes and other plants if you don’t know when or how to trim them correctly. For that reason, we’ve put together this helpful guide to teach you when to trim your landscape bushes, trees, and perennials.
When to Trim Bushes
When to trim bushes is dependent on the variety and bloom time of your shrub. For example, certain hydrangea bushes like ‘Limelight’ and ‘Annabelle’ are okay to trim anytime because they bloom on new growth versus old growth. Other varieties, however, bloom on old wood, which means if you prune too late in the season, you’ll be stripping away flower buds for next summer.
Most varieties of lilac, forsythia, smooth hydrangea, oakleaf hydrangea, and climbing hydrangea produce blooms on old wood that grew the previous year. If you want to trim these bushes, the best time to do so is right when they’ve finished blooming. Otherwise, you’ll remove flower buds, and these beautiful plants won’t produce prolific spring blooms.
In the fall, there isn’t much pruning that needs to be done, at least not until after your landscaping plants have gone dormant. If you trim your bushes too early, this can stimulate new growth when they should be settling in and readying themselves for dormancy..
When to Trim Rose Bushes
Rose bushes get a special mention because they can be pruned multiple times of the year. A major trim should be done in late winter or early spring. Deadhead regularly during the summer to encourage more blooms and keep your rose bush looking tidy. In the fall, after the first frost, go ahead and trim long canes and any that look diseased. You’ll also want to keep your rose bushes from being top-heavy so they don’t get damaged in winter storms.
When to Trim Trees
Deciduous shade trees like oak and ash are best to prune when they’ve gone dormant in the winter. This time of year makes it easier to see the branching structure, and it’s less likely to spread disease. Evergreens like Douglas fir, arborvitae, and spruce trees should be lightly pruned in the spring or early summer. In general, trees really only need pruning if there are dead or diseased branches that need removing or there is a desired shape you are trying to achieve. If you cut into an evergreen too deeply, you may end up with a bare patch and it may not produce new growth. However, it won’t hurt to trim a few tips off branches in midwinter if you wanted to add some festive greenery to your home.
When pruning established trees and shrubs, you can follow what is called the 1/3 rule. In essence, this means you trim 1/3 of the good wood on the shrub or tree, which will stimulate them to produce new growth and maintain a balance between the amount of greenery and the amount of water and nutrients they’re taking in from their root system.
When to Prune Perennials
Most summer-blooming perennials are better to prune in late fall. Some gardeners prefer to leave the dead growth and stems until next spring as they feel it offers winter protection for the plant and winter food for birds; this can be true, but it is important to cut back perennials that are prone to harbor pests and disease such as phlox, bee balm, hostas, daylilies, and peonies. Any perennials that tend to grow leggy, such as asters and sedums, can undergo a trim in July, which will most likely promote another fresh bloom cycle in the fall.
These are the basics for learning when to prune shrubs, trees, and perennials. For more pruning advice, stop by Meyer Garden Center in Moline, Illinois.