Pruning Trees
Pruning Shrubs
| |
Pruning - Why, When, and How
Pruning is an important but generally
poorly understood cultural practice. It's one of those garden tasks (like
pesticide application) that if it's not done the correct way at the right time
then it is probably best not done at all. We get questions about pruning all the
time at A World of Gardens and people often say "It took x number of years
to grow those branches and I just can't cut them off". Get over it, if done
correctly you won't hurt the tree and you may be surprised how much better it
looks and performs.
Ornamentals are pruned for any or all
of the following reasons: to remove broken, dead or diseased branches; to
encourage flower and fruit development; to control the size and shape of the
plant; to maintain healthy trees and shrubs; to increase structural strength and
to rejuvenate old flowering shrubs. When you prune a dormant tree, you remove
part of the top growth while leaving the existing root ball intact. When growth
starts the stored food and nutrients are shared between fewer buds and growth is
more vigorous.
The following are some general
guidelines as far as time to prune is concerned.
 | Broken branches should be cut
off immediately before they fall and damage the bark or other limbs. |
| Trees and shrubs that bloom in
the spring or early summer (forsythia, honeysuckle, mountain ash, lilacs)
should be pruned after flowering. |
| Fruit- bearing trees and
shrubs (apple, plum, cherry, currant) should be pruned in early spring
before they bloom. |
| Late flowering shrubs which
flower on new growth (shrubby cinquefoil, elderberry) should be pruned
before active growth begins. |
| Most evergreens are pruned
after the wood is thawed but before active growth begins. Pines are an
exception and are pruned after the buds are extended (candled) but before
the individual needles are fully formed. Take off only about half of the
‘candle' to avoid damage and poor formation of the new growth. |
| Some trees bleed sap freely
when pruned in the spring (birch, golden chain, poplar, maple) and are
better left until they are leafed out to cut down on sap loss. Avoid late
summer and early fall pruning because a new flush of growth encouraged by
the pruning may not harden off and turn from ‘green to brown' before
winter sets in. Late fall pruning can result in the wounds not healing until
spring and cause dieback of the cut branches. |
Many tools are available for pruning
and what you should use depends on the size of the material you are working
with. Branches up to ˝ inch can be cut with secateurs, up to 2 inches with
loppers, and larger limbs should be dealt with using a saw. If you don't have a
proper pruning saw , use a hacksaw. Pruning saws on a long pole are very useful
and save having to use a ladder. Working from the ground is easier and safer
then leaning over a ladder trying to get to that branch that is just out of
reach. Make sure your tools are sharp so that you make clean cuts the first
time, not ragged ones after several attempts. Clean cuts callous over and heal
quicker. Using sharp, well maintained (oiled, blades set correctly) tools is
easier on the tree or shrub and you.
When you decide to prune a tree or
shrub, look at the natural form or growth pattern. Try to enhance this look, not
change it. Avoid the "haircut" style of pruning where all branches are
cut the same length. This is okay for some shrubs but tends to cause too much
tip growth which can shade the centre of the plant and inhibit growth.
Your first cuts should remove all the
dead, broken or diseased branches. This is good practice and it is hard to go
wrong cutting off dead stuff. Using the proper tool for the size of the branch,
cut back to the "callus ring" ( a circle of raised tissue around the
base of the branch). Be careful not to damage this ring as it is the tissue that
will eventually close over the wound. Don't cut the branches off flush with the
trunk, this makes for a larger wound and removes the callus. You can use a
pruning paint if you want but this is more for looks than necessity. Your next
series of cuts will be to remove branches that are crossing over or rubbing each
other. This is especially important in the centre of the specimen where too much
material can cut down on sunlight and air reaching the crown of the plant and
contribute to pest and disease problems. Next have a good look and remove weak
or spindly branches. When shortening branches make your cut about 1/4 inch above
an outward facing bud at a 45° angle. This will keep the new growth going away
from the crown, leaving the centre open.
When removing larger
branches with a saw you will want to use the "jump" or three-cut
method to avoid having the branch tear the bark along the trunk when it falls.
Make the first cut from the bottom of the branch four to six inches away from
the callus ring. Cut upwards until you get about a third of the way through. The
second cut is made a couple of inches farther out and this one goes right
through, removing the branch and letting it fall. The undercut keeps the falling
branch from tearing the bark. Now that the weight of the branch has been
removed, the final cut can be made back to the callus ring. Either support the
branch stub when you cut it or cut through the bark from the bottom to avoid any
tearing. When pruning remember you can always take more off but sticking it back
on is a whole lot harder. Go easy, prune a little then have a good look and
maybe prune a little more.
Shrub
Pruning Calendar
Legend:
* = Best time to prune
x = Do not prune except to correct damage, hazards, or structural defects
- = Timing is not critical
Comments
- Flowers are produced on new
(current season) wood
- Flowers are produced on wood
from past season, pruning while dormant will reduce flowers
- Make pruning cuts well below
diseased wood (fire blight) - disinfect shears between cuts
- Remove old stems to ground
yearly to renew
- Midseason shear if a formal
hedge is desired
- Do not cut into old wood that
has no leaves or needles
- Spring/summer prune to remove
azalea caterpillars and galls
- Fall/early winter pruning can
reduce winter hardiness
- Snap candles (new growth) in
half when needles are 1/2 to 2/3 their normal mature length
Shrub Pruning Calendar
|
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
Comments
|
|
Almond, Flowering
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Arborvitae
|
*
|
*
|
*
|
-
|
-
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
6
|
|
Azalea, Deciduous
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Azalea, Evergreen
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,7
|
|
Barberry, Deciduous
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Barberry, Evergreen
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Beautyberry
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1,7
|
|
Beautybush
Kolkwitzia
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Boxwood
|
*
|
*
|
*
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
|
Butterfly-bush
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1
|
|
Cherry laurel (Prunus)
|
*
|
*
|
*
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
|
Clethra, Summersweet
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1
|
|
Cotoneaster, Deciduous
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
3
|
|
Cotoneaster, Evergreen
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
3
|
|
Daphne
Fragrant or Winter
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Deutzia
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Dogwood, Red twig
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1,4
|
|
Euonymus, Deciduous
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
|
|
Euonymus, Evergreen
|
*
|
*
|
*
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
|
Forsythia
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Hibiscus,
Rose of Sharon,
Althea
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1
|
|
Holly, Evergreen
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,5
|
|
Honeysuckle
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4,5
|
|
Hydrangea, Spring-blooming
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Hydrangea, Summer blooming
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1
|
|
Hypericum, St. Johnswort
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
1
|
|
Juniper
|
*
|
*
|
*
|
-
|
-
|
-
|
-
|
x
|
x
|
x
|
*
|
*
|
6
|
|
Kerria (Globeflower)
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Lilac
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Mahonia
Oregon Grape holly
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Mock orange
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Pieris
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Pine, Mugo
|
*
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
*
|
9
|
|
Privet, Deciduous
(Ligustrum)
|
*
|
*
|
*
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
|
Privet, Evergreen
(Ligustrum)
|
*
|
*
|
*
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
|
Potentilla
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
1,4
|
|
Pyracantha
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,3
|
|
Quince
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Rhododendron
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Rose
|
x
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
1,3,4
|
|
Serviceberry
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
|
|
Smoke Tree
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
*
|
*
|
1
|
|
Spirea
Spring-blooming
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Spirea
Summer-blooming
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
x
|
1
|
|
Sumac
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
*
|
1,4
|
|
Viburnum,
Deciduous
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Viburnum,
Evergreen
|
x
|
x
|
x
|
x
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Weigela
|
x
|
x
|
x
|
x
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2,4
|
|
Willow, Pussy
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Witch hazel
|
x
|
x
|
x
|
*
|
*
|
*
|
*
|
x
|
x
|
x
|
x
|
x
|
2
|
|
Yew
|
*
|
*
|
*
|
-
|
*
|
*
|
*
|
x
|
x
|
x
|
*
|
*
|
5
|
Exceptions
- Prune anytime to correct
vandalism and hazards created by equipment or weather
- Hedges maintained formally
(tight shapes) require more pruning than hedges maintained informally (in
their natural form)
|
