GARDENING FACT SHEET:
Click to View Printable PDF file: “Pruning Shrubs”
Summer blooming shrubs
Summer blooming shrubs (which usually bloom after June 15th) bloom on new growth. Pruning should be
done in the fall or late winter.
Examples of summer blooming shrubs:
- Butterfly Bush
- Blue Mist Spirea
- Mock Orange
- Potentilla
- Japanese Spirea
- Hydrangea
Spring blooming shrubs
Spring blooming shrubs bloom on last year’s wood. Pruning in the fall and winter will remove buds set to
bloom in the spring. Pruning should instead be done right after blooming.
Examples of spring blooming shrubs:
- Forsythia
- Lilac
- Vanhoutte Spirea
- Viburnum
- Weigelia
How to Prune Shrubs
Prune off any broken, damaged or pest-ridden branches and remove any branches that rub against each
other. Then decide on the correct pruning method. The correct pruning method depends on the kind of shrub
you have and whether you are pruning to encourage new growth, for aesthetic reasons or to treat damage.
Rejuvenation Pruning
Rejuvenation pruning is cutting a shrub almost to the ground to encourage new growth. Examples of shrubs that may benefit include Russian Sage, Butterfly Bush and Spirea. Rejuvenation pruning should never be used on tree-like shrubs and should only be done every 3-5 years. The exception is Russian Sage and Butterfly Bush which benefit from a yearly rejuvenation pruning.
Thinning
Thinning is systematically removing old wood branches to encourage new growth. Select the oldest, woodiest
branches first and remove one third of the branches each year. Works well on Lilac, Forsythia and Ninebark. Does not work well on Spirea or Potentilla.
Shaping
Shaping is pruning to a desired shape or size. It should not be used to try and keep large shrubs very small.
Instead choose a variety that has a full-grown size better suited for the spot in your yard.
Never prune more than 1/3 of the plant’s branches.
Click to View Printable PDF file: “Pruning Shrubs”
