Pruning Calendar

How to use the pruning calendar

Pruning is timing as much as technique. Cut a spring-flowering shrub in winter and you remove the flower buds it spent last summer forming; cut a summer-flowering shrub in summer and you remove the flowers themselves. This calendar gives you the right window for common garden plants, adjusted for your zone — colder zones prune later in spring, warmer zones earlier — so you can prune with confidence instead of guessing.

The one rule that explains most of pruning

Almost every pruning decision follows from a single question: does this plant flower on old wood or new wood? Plants that flower on old wood — lilac, forsythia, azalea, mophead hydrangea — form their flower buds in the summer and autumn before they bloom, so they must be pruned just after flowering. Prune them in winter and you cut off next spring's display. Plants that flower on new wood — roses, butterfly bush, panicle hydrangea, crape myrtle — make their flowers on the current season's growth, so they are pruned in late winter or early spring, before growth starts. If you remember nothing else, remember this: spring bloomers get pruned after they flower; summer bloomers get pruned before they grow.

Fruit trees and vines follow the same dormant-season logic. Apples, pears, peaches, grapes and blueberries are pruned in late winter while fully dormant, when you can see the branch structure and the plant can heal as growth resumes. The exception is stone fruit in very cold zones, where pruning is sometimes left until buds swell so winter damage is visible first. Raspberries are the one plant where the calendar depends on the type: summer-bearing canes are cut out just after fruiting, while everbearing types are cut to the ground in late winter for a single autumn crop.

How to prune, not just when

Good pruning starts with the three Ds: dead, damaged and diseased wood comes out first, at any time of year — that is maintenance, not seasonal pruning, and it never waits for the calendar. Next, remove crossing branches that rub each other, and any growth heading into the centre of the plant; the aim is light and air reaching the middle. Make clean cuts just above an outward-facing bud or a side branch, at a slight angle so water runs off, and use sharp, clean tools — a blunt cut crushes the stem and invites disease, and tools used on a diseased plant should be wiped with disinfectant before they touch a healthy one.

The most common beginner mistake is over-pruning. A healthy shrub should never lose more than about a quarter of its growth in one year, and a tree no more than a quarter of its canopy. Renovation pruning — cutting an overgrown shrub hard to the ground — works for some tough plants (butterfly bush, spirea, forsythia) but kills others, notably lavender, which rarely regrows from old bare wood. When in doubt, prune lightly and come back next year: you can always take more off, but you cannot put it back.

Mistakes worth avoiding

Never “top” a crape myrtle or any tree — cutting the top off produces a flush of weak, ugly shoots and a tree that is permanently misshapen. Never prune spring-flowering shrubs in autumn or winter unless you are happy to sacrifice the flowers. Avoid pruning in late autumn: the soft new growth that follows a cut is easily damaged by frost. And do not prune in wet weather if you can avoid it — fungal spores spread easily on wet tools and fresh cuts. Finally, remember that the calendar gives windows, not dates: a lilac in zone 4 finishes flowering weeks later than one in zone 8, so watch your own plants. When the flowers fade, that is the signal — the calendar just tells you roughly when to expect it.

Related tools: plan the rest of the month with the Garden Planner, check your hardiness zone if you are unsure which window applies, and see what to plant this month. For plant care by species, browse the houseplant hub.