October is an ideal time to prune many common garden staples, including perennials, shrubs, hedges, and trees. However, not all plants should be pruned in October. Some plants, such as azalea, viburnum, Loropetalum, and lilac, cannot handle fall pruning. The best time to prune a flowering tree, shrub, or vine is after it finishes blooming. Prune summer-flowering woody plants in late fall or winter. Ignore this rule, and your plant probably wont bloom the next year. Here are some plants that can be pruned in October:
- Angels Trumpet: Prune after it has ceased flowering over the fall and winter months.
- Butterfly Bush: You can clip several butterfly bush species in the fall. However, you should only prune Buddleia alternifolia and Buddleia x pikei Hever (Hever Castle) after they bloom as they flower on new growth.
- Knock Out Rose: Prune anytime except for late summer and early fall. Any other time of year—late fall included—you can take advantage of a post-blooming resting period by cutting them back by one-third.
- Lavender: Some selections of English lavender (Lavandula angustifolia) can be pruned in the fall.
- Shrub roses: It’s best to tackle rose pruning in winter or early spring when plants are dormant. However, if you have large or overgrown shrub rose bushes and you’re in an area prone to heavy snows that could break canes, pruning to remove 2 to 4 inches of canes can help protect the plant. If shrub roses have overtaken walkways, remove the problem canes. Wait to prune until after several hard freezes, or you risk triggering new growth.
- Plants prone to slugs: Slugs lay eggs in fall, so once a few frosts knock back plants, cut stems and leaves of hosta, delphinium, lupine, and any other plant slugs attacked in force. Do not compost prunings; destroy them.
- Mediterranean shrubs: Sun-loving shrubs that will not tolerate hard pruning in winter, such as rosemary, lavender, and cistus, should be cut back after flowering but before winter.
Its important to note that the timing window for these pruning chores is from Thanksgiving to the New Year.
