The proper way to make a cut is illustrated above. Cut Ό
inch above the bud at a 45-degree angle. Prune to an outward
facing bud to encourage growth away from the center of the
plant, resulting in a more graceful shape.
The primary types of cuts include:
above) selective pruning of a terminal shoot or
branch back to a lateral bud. This type of cut stimulates growth
at the tips of the branches. However, excessive tip growth
shields the interior of the plant from light penetration and air
movement. Over time, and with repeated heading back, the plant
develops a dead zone of woody stems that dont produce any new
growth. This type of pruning results in high-maintenance plant
a type of heading cut, but without regard to where the cuts
are made along the branch. Shearing is used to create topiaries
and the geometric shapes often found in formal gardens.
above) removing a branch or stem where it joins
another branch. This technique allows light and air to penetrate
throughout the plant. In addition, proper thining retains the
plants natural growth habit. This type of pruning is suitable
for virtually any woody plant.
removing a portion of the oldest stems at ground level. This
opens the interior of the plant to light and air movement.
Complete renewal pruning is a three-year process. One-third of
the oldest stems are removed in late winter to early spring. The
following year, another third of the oldest stems are removed at
ground level. Year 3 concludes with the remaining third of the
old stems being removed. Renewal pruning results in complete
renovation of the plant. This technique can be used on many
plants and is particularly valuable for controlling large,
Rejuvenation removing all stems down to 4-12-inches above the
ground. This technique results is a completely new plant for the
growing season. Plants such as, red-twig dogwood, spirea,
forsythia and butterfly-bush can withstand this drastic pruning.
Shrubs are the best candidates for DIY pruning because they are
more forgiving of improper pruning. Shearing shrubs whose
natural habit is sprawling or upright and multi-branched into
tight specimens diminishes their natural beauty.
pruning is required for a young or mature tree, consult an
arborist, nursery personnel or an experienced gardener. Improper
pruning can result in a permanently disfigured tree, leading to
insect, disease and structural problems in the future. Do not
attempt to shear or prune a tree whose mature size ranges in the
40-100 foot range into a specimen suitable for a small garden.
Seasonal Pruning Guidelines
Some rule-of-thumb guidelines:
Know the genus, species and cultivar of the plant you are
pruning. Consult the plant tag or research its mature size. Know
when it blooms as well as if it flowers on old or new growth.
Dead and broken plant parts can be removed anytime of the year.
Diseased plant parts should be removed as soon as possible.
Disinfect pruners when working with diseased tissue.
If a plant has crossing branches that rub against each other,
remove one of the branches to prevent insect/disease entry
If a plant blooms in spring (March through May), wait until
after blooming is completed to prune. Examples include
rhododendron, forsythia, lilac and mockorange.
Plants that bloom in summer or fall are best pruned in March
through early April. Examples include abelia, butterfly-bush,
caryopteris and some spireas.
Hydrangea, clematis and roses have varying pruning schedules
beyond the scope of this article. Use the resources below to
explore specific plants and their pruning needs.
Internet, garden nurseries and experienced gardeners
Any Penn State Extension Office for Allegheny County, call
Two excellent publications from Penn State Extension include:
A good reference book covering all aspects of pruning is The
Pruning Book completely revised and updated by Lee Reich.