Pruning Tips

According to Susan Gruber, Briggs & Stratton Yard Smarts horticulturalist, this is a simple guide for when to prune in your garden to create healthy, good-looking, and long-lasting plants:

Early Spring (March-April)

Plant type: Ornamental grasses
Task: Cut as close to the ground as possible.
Tip: Tying the tops before cutting makes the job fast and easy.

Plant type: Semiwoody perennials (butterfly bush, Russian sage)
Task: Cut back to about 4" to produce strong new stems and best flower display.
Tip: May be cut back anytime during the winter.

Plant type: Broad-leaved evergreens (boxwood, holly firethorn)
Task: Prune out stems with winter-injured foliage.
Tip: Wait until later in the spring to shear or hedge so new growth will quickly cover cut tips.

Plant type: Summer-flowering trees, shrubs, vines, hydrangea, and roses
Task: Remove dead, damaged, or crowded stems, shape or reduce size if desired.
Tip: Summer flower buds develop on new growth. Spring fertilization and adequate moisture in the summer will maximize number and size of summer blooms.

Spring/Early Summer (May-June)

Plant type: Spring-flowering shrubs (forsythia, rhododendron, lilacs)
Task: Prune for shaping or size control following the "prune after flowering" rule. These plants form buds for next year's flowers during the summer. Pruning after midsummer 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 multistemmed 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: Evergreen shrubs (yews, juniper, boxwood)
Task: Hedging and shaping if desired or thinning to reduce size.
Tip: Cut just as growth begins so new growth covers cut tips. Each job should include some inner thinning of the bush to ensure the outside layer of foliage doesn't become very thick, resulting in a thin shell of very dense foliage that is attractive to insects.

Midsummer/Fall (July-November)

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 (December-February)

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.