When to prune shrubs depends on when they bloom. Prune native shrubs that flower in summer, like buttonbush and elderberry, in late winter. Prune spring bloomers, like viburnum and chokeberry, right after the flowers fade. Don't prune from August through November. Dead or broken wood can come off any time.
This is Tennessee Wholesale Nursery's garden almanac. We are a family-owned wholesale nursery in Altamont, Tennessee, near McMinnville. We grow trees, shrubs, perennials, and wetland and native plants. This calendar covers the native shrubs we grow. The dates fit USDA zones 6 and 7, which cover most of Tennessee. If you garden farther north, shift each step a week or two later.
When to prune shrubs: why timing matters for flowers and berries
Every shrub makes its flower buds at a set time. Some form them the summer before, on last year's stems. Gardeners call this "old wood." Others form buds on stems that grow this spring, called "new wood."
- Cut an old-wood shrub in winter, and you cut off this spring's flowers.
- Cut a new-wood shrub in winter, and it simply grows fresh stems that bloom on time.
- On native shrubs, a lost flower is also a lost berry. No bloom means no fruit for you or for the birds that feed on it in fall and winter.
Penn State Extension gives the same rule of thumb in its guide to how and when to prune flowering shrubs: shrubs that bloom in spring go after flowering, and later bloomers go in late winter or early spring.
Native shrub pruning calendar, month by month
| Month | What to do | Native shrubs to prune |
|---|---|---|
| January | Remove dead, broken or storm-damaged stems. Leave the berries. | All (dead wood only) |
| February | Main late-winter pruning while shrubs are bare. Take suckers off witch hazel. | Buttonbush, elderberry, witch hazel |
| March | Finish late-winter cuts before buds open. Spicebush blooms now, so leave it be. | Buttonbush, elderberry |
| April | Light shaping once flowers fade. | Spicebush |
| May | Thin right after the flowers drop. | Blackhaw viburnum, Carolina allspice, black chokeberry |
| June | Thin right after bloom. Aim to finish after-bloom cuts by early July. | Arrowwood viburnum |
| July | Small cleanup cuts only. Buttonbush and elderberry are in flower, so leave them. | None |
| August | Put the pruners away. Cuts now push tender growth before frost. | All (dead wood only) |
| September | No pruning. Berries are ripening. | All (dead wood only) |
| October | No pruning. Leave fruit for migrating birds. | All (dead wood only) |
| November | No pruning. | All (dead wood only) |
| December | Rest. Note which shrubs need work next year. | All (dead wood only) |
Native shrubs to prune in late winter
These shrubs bloom in summer on new wood. A late-winter cut costs you no flowers. It also lets you see every branch while the leaves are off.
- Button Bush Shrubs: known for round white flower heads in summer. Cut the oldest stems to the ground in February or March. You can cut an overgrown plant back hard, and it will regrow.
- Elderberry Shrub: its canes bear best when they are young. Each late winter, cut out the oldest, woodiest canes at the base. Keep a mix of one- and two-year-old canes.
Native shrubs to prune right after they bloom
These shrubs bloom in spring on old wood. Prune within a few weeks after the flowers fade. That gives them all summer to set next year's buds.
Tip: On berry shrubs, every stem you cut after bloom takes this year's fruit with it. So thin, don't shear. Remove a few whole stems at the base and leave the rest to fruit.
- Black haw Viburnum: bears white flower clusters in spring. Thin it in May, once the petals drop.
- Arrowwood Viburnum Shrub: flowers a little later. Thin it in June. Take out the oldest stems to keep it full at the base.
- Carolina Allspice Shrub: known for its deep red flowers. Shape it lightly after bloom and remove suckers that wander too far.
- Black Chokeberry Shrub: grown for its dark berry clusters. Thin a few old stems after bloom and leave the rest to fruit.
Native shrubs to leave mostly alone
Some natives grow into a good shape on their own. Pruning them mostly costs you flowers. Remove only dead, broken or crossing branches.
- Northern Spice Bush: one of the first shrubs to bloom in early spring, on old wood. If it needs shaping, do it in April after bloom.
- Witch Hazel Shrub: this is Hamamelis virginiana, the native witch hazel that blooms in fall, when little else does. Take suckers off at the base in February, and leave the main branches alone.
Is October too late to trim shrubs?
Yes, for most shrubs. From August through November, a cut tells the shrub to grow. The new shoots are soft when the first frost comes, and they die back. Wait for late winter or for the next bloom to pass.
Fall is also when native shrubs pay you back. Viburnum, chokeberry and spicebush berries feed birds through fall and winter. Leave them on the plant. Dead or broken branches are the one exception: remove those any time.
How to make the cut on a native shrub
Most native shrubs grow as a clump of stems. The best way to keep them young is renewal pruning. That means taking out a few of the oldest stems each year, right at the ground.
- Start with dead, broken or diseased stems.
- Next, remove stems that cross and rub against each other.
- Then cut up to one-third of the oldest, thickest stems at the base.
- Use clean, sharp hand pruners or loppers. Cut just above a bud or flush at the base.
- Step back often. Stop once light and air reach the middle of the shrub.
Avoid hedge shears on native shrubs. Shearing clips the tips where flowers and berries form. It also leaves a dense shell of twigs with a bare center.
Pruning questions
Is April too late to trim bushes?
Not for spring bloomers that have just finished, like spicebush. April is the right time to shape them. It is late for summer bloomers like buttonbush and elderberry, which have already begun new growth. For those, make only small cuts this year, or skip a year and prune in late winter.
Is it okay to prune shrubs in July?
Light cleanup is fine, such as a broken branch or a stem blocking a path. Try to finish after-bloom pruning of spring bloomers by early July. After that, viburnum, chokeberry and allspice are setting next year's flower buds, and late cuts remove them along with next year's berries.
Can you trim a bush that is blooming?
You can, but you lose those flowers and the berries that would follow them. It is better to wait until the blooms fade, then prune within a few weeks. Cutting a few stems for a vase does little harm, since it takes only a small share of the shrub.
When to prune viburnum?
Prune native viburnums right after they bloom. In Tennessee that is usually May for blackhaw and June for arrowwood. Thin a few of the oldest stems at the base, and leave the rest to set berries. Avoid winter pruning, which removes the flower buds already formed.
