Pruning Trees and Shrubs

Reasons for pruning are to remove broken or damaged branches, to shape, to thin out dense or dead branches and to maintain the health and quality of the plant. Pruning at the correct time will help minimize flower and fruit loss as well as minimize potential of disease. Below is a list of common plants and when to prune:

  • Oaks and Elms: should be pruned during December, January or February during dormancy to minimize the chance of oak wilt or dutch elm disease infection. Disinfect pruning equipment between each cut.
  • Apples, Crabapples, Pears, Mountain Ash, Hawthorns, Cotoneasters: should be pruned mid to late winter to minimize the chance of fireblight.
  • Maples, Honeylocust, Butternuts, Walnuts, Birch, Ironwood: have free flowing sap and will “bleed” if pruned in late winter or early spring. This “bleeding” does not cause any harm to the tree, however, will be prevented if pruning is done anytime there is active growth.
  • Trees and shrubs that bloom early in the growing season on old wood should be pruned immediately after they finish blooming:
    • lilacs
    • azalea
    • hollies
    • pearl bush
    • deutzias
    • forsythias
    • nikko blue hydrangea
    • rhododendrons
    • magnolias
    • flowering almonds
    • early spireas (such as bridalwreath)
  • Shrubs that bloom late spring but on old wood should be pruned either early in the spring before growth starts or immediately after bloom:
    • mockoranges
    • potentillas
    • weigela
    • old roses
  • Shrubs grown primarily for their foliage or fruit should be pruned in the spring before growth starts:
    • barberries
    • buffaloberries
    • peashrub
    • cistena sandcherries
    • cranberries
    • dogwood
    • euonymus
    • ninebarks
    • alpine currants
    • honeysuckles
    • sumac
    • smokebushes
    • winterberries
    • viburnums
    • chokeberries
  • Shrubs that bloom on the current season’s growth should be pruned in the spring before the growth starts:
    • most clematis (to live wood)
    • annabelle and peegee hydrangeas
    • garden roses (to live wood)
    • most pink flowering spireas
  • Evergreens that grow continuously through the growing season can can pruned at any time, but early in the growing season is usually best:
    • junipers
    • white cedar or arborvitae
    • yew and hemlocks
  • Pines put on a single flush of growth each year. They must be pruned at the candle stage, remove 1/2 to 1/3 of new growth.