Knowing exactly when to prune is an important step in keeping plants healthy. Use our seasonal guide to plan your gardening calendar.
EARLY SPRING: Ornamental Grasses
EARLY SPRING: Perennials
Plant type: Semiwoody perennials (butterfly bush, Russian sage)
Task: Cut back to about 4″ to produce strong new stems and the best flower display.
EARLY SPRING: Flowers
EARLY SUMMER: Evergreen shrubs
Plant type: Evergreen shrubs (yews, juniper, boxwood)
Task: Hedge and shape, if desired, or thin to reduce size.
EARLY SUMMER: Flowering Shrubs
Plant type: Spring-flowering shrubs (forsythia, rhododendron, lilacs)
Task: Prune for shaping or size control after flowering. These plants form buds for next year’s flowers during the summer. Pruning after mid-summer will cut off flower buds.
Tip: Deadheading — remove fading flowers — benefits plants like rhododendron and lilac by preventing seed formation and directing growth into flower buds for next spring. Thinning multi-stemmed shrubs by removing several of the oldest stems each year will maintain size and keep plant vigorously blooming on new stems.
If any of these plants, like forsythia and lilac, are overgrown, cut down to 3″ to 4″ for a fresh start. A drastic procedure for problem plants growing too vigorously in full sun, this technique is called “rejuvenation” and is not for the timid gardener!
Plant type: Flowering perennials and annuals
Task: Deadheading — removing flowers as they fade — extends the flowering or promotes a second flush of flowers. After the frost in your area, when perennials and annuals have died, cut down and mulch the area well for next year’s growth.
Tip: Do not deadhead if dried flowers or seed are attractive or desirable for propagation. During this time, woody plants will not produce callus; the tissue that covers pruning wounds. Fungal spores, bacteria, and insects are all abundant and can find a foothold in an open wound.
WINTER: Deciduous Trees and Evergreens
Plant type: Deciduous and evergreen trees, crab apples and other pest-prone plants
Task: Remove any dead, damaged, or hazardous limbs. Prune limbs that interfere with walkways and structures. Remove crossed or rubbing limbs. Prune out suckers.
Tip: Winter is a great time to prune; insect and disease pressure is minimized, and the plant architecture is visible.