from This Old House
Prune these specimens in the late winter or early spring for thicker foliage later on.
In zones where winter has put plants in sleep mode, now’s the best time to prune certain specimens. Use heading cuts to prune back to a healthy bud and promote side branching, and thinning cuts, which take the branch to the nearest limb, to maintain the plant’s shape. Snip smart, and you’ll see more blooms and thicker foliage.
What to Prune in Early Spring
Summer-flowering deciduous shrubs
These are shrubs that bloom on new growth, such as butterfly bush, rose of Sharon, and crape myrtle.
When and why: These are still dormant in late winter/early spring, making it easy to see your cuts—and they’ll heal up quickly with the flush of new growth in spring, which is when the shrubs set the summer’s buds.
Examples of conifer trees and shrubs include arborvitae, juniper, yew, and holly.
When and why: Prune in early to late spring, once lighter-colored new growth appears, which gives time for cuts to heal and new buds to form. Use thinning cuts back to the main stem to tame overgrown shrubs; for heading cuts, prune back to a branch that has needles or leaves on it so new growth can sprout.
Deciduous perennial vines
These types of vines bloom on new growth, such as trumpet vine, climbing hydrangea, and Boston ivy.
When and why: Heading cuts in late winter or early spring control growth and encourage branching. Ivies can be trimmed anytime, but save heavy shaping of deciduous varieties for late winter/early spring, before leaves appear.
Wait on Pruning These Specimens
Prune azaleas and rhododendrons in spring or early summer, after flowers wither, so as not to remove next year’s buds and reduce blooms.
Traditional mophead hydrangea sets buds on the previous year’s growth, so while it’s safe to snip spent flowers and dead branches, avoid major shaping until summer’s end.