As your garden is beginning to go to sleep for the season, you may be ready to do some autumn cleanup. And while it’s fine to rake up leaves (and compost them!), pull faded annuals or plant spring-flowering bulbs, there are many shrubs you shouldn’t prune in the fall—and some you should never prune! If you’ve ever wondered why a shrub isn’t flowering, it may be that you pruned it at the wrong time last year. In fact, many flowering shrubs bear flower buds on last year’s wood, known as “old wood,” so if you cut them back now, you’re cutting off next year’s flowers. And if you prune any shrub too late in the season, you’ll stimulate new growth, which will not have time to harden off (or toughen up) before a freeze. This can damage and weaken the plant, so leave pruning until next year.
So, save yourself some work now and frustration later, and put down those pruners! Here are the most common shrubs and perennials you shouldn’t prune in the fall:
1. Oakleaf Hydrangea
Oakleaf hydrangea, which has leaves that somewhat resemble an oak tree, is a gorgeous shrub with lovely papery blooms from summer to fall. It also boasts bright autumn color, and some flowers remain intact all year to provide winter interest. But don’t cut oakleaf hydrangeas back like you do other types of hydrangeas, such as panicle hydrangeas, which bloom on new wood. Oakleaf hydrangeas bloom on old wood and never need trimmed except to cut off dead branches that don’t leaf out next spring.
Just when you need color the most after a long winter, this shrub bursts into bloom in early spring. Many types of forsythia can get large and unmanageable, so you may be tempted to hack them back in the fall. However, you’ll remove the buds that form next year’s bright yellow blooms. If your shrub has gotten too big, trim it next spring immediately after it finishes blooming. And next time, plant a new dwarf variety that will stay nice and compact.
Lilac is a gorgeous, old-fashioned shrub with spikes of fragrant purple, pink or white fragrant flowers in late spring. But if you prune in fall, you’ll chop off the blooms for next year. It should rarely be trimmed except to cut off dead branches. Also, look for new dwarf and reblooming varieties if you want to plant a new lilac.
This native shrub has a lovely arching shape with green, chartreuse or dark burgundy leaves and tiny pink or white flowers in the spring. It’s actually a shrub you should never prune, except to trim back any dead branches when you see them. Otherwise, leave it be so you don’t destroy its shapely form.
Rhododendrons have glossy evergreen leaves and gorgeous clusters of flowers in pinks, purples and white in the spring. But if you prune now, you’ll cut off next year’s flowers. If your shrub needs neatened up, trim immediately after the flowers fade in the spring.
Azaleas also bloom on old wood, with next year’s flowers forming months after the current year’s flowers have died back. Prune only immediately after flowering if you need to shape it.
This stunning shrub has gorgeous tube-shaped flowers that pollinators love, and you’ll totally miss out on them next year if you trim them in the fall. You’ve been warned.
The beautiful, fringe-y flowers of this plant appear in mid-spring. If you do need to shape it, trim it immediately after it finishes flowering.
9. Mountain Hydrangea
Like oakleaf hydrangeas, this type of hydrangea doesn’t need (or like) being pruned. While it’s fine to remove dead wood, don’t do it until late spring when the plant has leafed out so you can see what you’re doing.
This charming, pollinator-friendly shrub has a delicate arching form and tons of delicate pink flowers in late spring. Keep your pruners away from this shrub unless you need to remove a dead branch.
PureWow may receive a portion of sales from products purchased from this article, which was created independently from PureWow's editorial and sales departments.