PRUNING WOODY ORNAMENTALS
Sanitation is of primary importance when pruning. I spray my pruning equipment
with alcohol or Listerine® at a minimum between each plant. If I suspect
diseases, spraying more often is desirable. Bleach is better than alcohol
but more toxic to the environment and may be bad for the ozone layer.
I do not like spraying bleach around my plants and me. The wind usually
blows it in my face and produces little white dots on my clothes and plant
leaves. Another excellent one to use is Lysol®.
Sharp tools are another concern. It is surprising how many people struggle
with dull pruners that crush and tear off the branches instead of leaving
a nice clean cut. Please use sharp tools.
Definitions used in this article on woody ornamental pruning
APICAL CUTTING The repeated shearing or cutting
back of a plant’s top growth. This technique results in brooming
of the top growth, a main branch with many smaller branches forming at
its tip. Hedge trimmers are notorious for producing brooming. After some
years, much of the plant is dormant or dead in the inside. For example,
repeated over many years, it commonly results in yews or junipers incapable
of being pruned back to a manageable size.
BARK The protective surface layer on a trunks and
branches. Usually composed of dead, corky cells on the outside and are
continuously added to during the growing season on the inside. This cell
growth also allows for the expansion of the woody interior. As the woody
interior grows larger each year, the oldest bark tissue splits, thereby
allowing for continued expanding growth. A plant can be commonly identified
by its bark and its bark splitting pattern. Bark makes one of the best
garden mulches. The interior wood is not as good for mulching.
BARK INCLUSION A narrow or appressed junction between two or more branches
where bark formation continues to develop. This is similar to the folding
of skin between your index finger and your thumb when your thumb is held
against the side of your palm. Bark inclusions gradually push the adjacent
limb out from the primary one causing severe stress on the internal wood
structure. Wind and snow load gradually exceeds the internal woods’
carrying capacity causing it to break and tear away from the dominant
limb. Healing or compartmentalization from such a break it difficult and
often allows rot to enter the dominant’s wood.
BUD A tight dormant bundle along and atop a stem containing undeveloped
leaves, stems and or flowers. Upon expanding, it becomes leaves, shoots
or flowers.
CALLUS Corky tissue arising from the cambium (the active growth region
between the bark and wood). This callus tissue gradually heals or compartmentalizes
a wound allowing for closure & hopefully, new wood and bark.
COLLAR The area where a secondary branch attaches to a primary or carrier
limb. This area is typically wrinkled with concentric bark folds. Whenever
pruning always avoid damage to the collar as this area gives rise to the
compartmentalization callus.
COMPARTMENTALIZATION Woody ornamentals cannot heal like humans. Callus
tissues must form a compartment around the wound. This compartmentalization
of the wound seals it off from the weather, diseases and insect pests.
CONIFERS A cone bearing plant typified by Fir, Spruces, Pines, Yews, Arborvitaes
and Hemlocks.
COPPICE Cutting away most if not all of the new growths on a shrub such
as willow, hazelnut, or dogwood to encourage rapid production of long
straight vigorous stems or a coppice. Repeated coppice pruning produces
a stool basal trunk from which arise many fresh and vigorous stems.
CROTCH The junction point of a branch to a primary limb or trunk. Narrow
crotches are typically weak whereas 90-degree crotches are generally very
strong. If you can rotate your finger in a crotch, it is generally healthy
and strong. If you cannot, consideration should be given to remove the
secondary limb.
DECANDLING On conifers, decandling is the total or partial cutting or
twisting off of the immature growth. This reduces the amount of annual
growth and enhances branching.
DEEP PRUNE Pruning out branches as deep inside the structure of the plant
as possible while maintaining its form. Conifers can be deep prune only
to a vigorous branch or live green shoot. Pruning below a green shoot
usually results in the death of that branch. Conifers cannot be renewed
or rejuvenated like most deciduous shrubs.
DECIDUOUS Woody ornamentals that loose their leafs at least one a growth
cycle. In Wisconsin this generally occurs in the Autumn
DESUCKERING The removal of new vigorous basal shoots to maintain a mature
tree form. Cut as close as possible to the trunk without damaging the
collar
.
FEATHER Pruning to form a three-dimensional branching habit of a bird’s
feather replete with balance & structure
.
FLUSH A rapid production of growth occurring over a short period of time.
Yews commonly have up to 3 flushes of growth per season.
HARD PRUNE Cutting the entire shrub or bush to within 6-8" of the
ground, allowing for the entire plant to renew itself.
HEALTH - STRUCTURAL The removal of broken, damaged, dead, diseased, malformed,
crossing or non-aesthetic limbs and branches.
LATERAL A side-growth or branch. These generally form the desirable architecture
of a plant.
LOPPING Irreverent topping of a tree or shrub to reduce its height without
regard for its future health. Lopping generally result in numerous co-dominant
shoots and a non-compartmentalizing infected wound.
NEW WOOD FLOWERING Blooming on current year’s growth such as Hibiscus,
Goldflame Spiraea and Tea roses.
OLD WOOD FLOWERING Blooming on last year’s growth such as Lilac,
Bridal Wreath Spiraea, Magnolia, Crabapple, and Viburnum.
POLLARD A lopped off branch. Annual decapitations provide for the formation
of long shoots giving the bush or tree a unique full mop-head appearance.
PRUNING The removal of undesirable growth, promoting desirous growth.
RENOVATE / RENEW The complete removal of all stems to a specified height
above the ground.
REMOVAL Cut the plant to about 24” above grade and then digging out
stump. If it is too large, wrap a chain around the stump and pull it out
of the ground with a Bobcat7. Throw all stems and trunks onto the compost
pile or in the trash. Treat any sprouts with ROUNDUP7 or similar herbicide.
This is the preferred technique for treating Lonicera tartarica et al
and Rhamnus cathartica et al.
REJUVENATE The partial and systematic removal of old and/or overly mature
woody branches leaving and encouraging more vigorous and healthier younger
and new growth.
REVERSION A shoot that has reverted to the original parent form and no
longer shows the desirable characteristics. Prune out reversions to their
source.
RIVAL Co-dominant limbs. Remove the lesser of the two or three where possible.
SHAPING The removal of growth, conforming it to a more desirable shape.
SHEARING Evenly cutting the entire plant back to a given height without
regard to branching and health. Some plants such as boxwood tolerate this
form of pruning remarkably well.
SHEDDING or Limb Cast. The is the sudden horrifying unprovoked dropping
of a major limb. This commonly results in a tear and should be assessed
by an arborist immediately.
SHOOT A plant’s rapidly expanding growth that matures to a stem or
branch.
STOOL A stump or rootstock that produces numerous young shoots or suckers.
See COPPICE.
SUCKER Branches or shoots arising from the base or stock of a grafted
plant. These shoots typically siphon the vitality from the scion or desirable
grafted plant. Prune suckers as flush to the trunk as possible yet avoiding
damage to the collar.
TEAR A wound caused by the ripping of a secondary branch or limb from
its primary limb. The tear dislodges the bark from the primary limb in
a v-shaped pattern pointing downward along the primary limb. Healing is
difficult. Think of a really bad hangnail tear.
WATER SPROUT or EPICORMIC Branches derived from buds that form beneath
the bark. They may result from damage but not always. Common on fruit
trees, they arise from mature limbs as vertical straight branches. Prune
as flush to the trunk as possible yet avoiding damage to the collar.
WHIP A very young tree with an erect or excurrent stem and no laterals
or side branching.
WOOD The beautiful hard inner or xylem part of a trunk, limb or branch.
WOODY ORNAMENTAL A plant having persistent woody stems in all seasons.
THE PRUNING OF TREES, SHRUBS AND CONIFERS by GEORGE E. BROWN & THE
ESSENTIAL PRUNING COMPANION by PROFESSOR JOHN MALINS
are excellent books on pruning.
PRUNING RECOMMENDATIONS BY GENUS
ABIES Firs. Dwarf types are decandled when shoots have matured 50%. Health
or deep prune trees in Winter.
ACER Maples. Co-dominance and tight crotches are occasional problems.
Up prune to allow movement under the tree. Prune in fall to early spring
.
AMPELOPSIS Porcelain Vine is sheared back up to 80% in March.
BERBERIS Barberry can be rejuvenated by up to 80% in March.
BETULA Birch is pruned in the spring removing tight crotches and removing
lowest branches to allow walking or working under them. On dwarf birch
only prune to maintain shape or deep prune if height reduction is desired.
CARYOPTERIS Blue Mist is annually renewed in April once growth is noticed.
CHAMAECYPARIS Hinoki Cypress and other types are health, structure or
deep pruned in Winter or following first flush in summer.
CLEMATIS Spring blooming types should be lightly renovated post flowering.
Most summer blooming types can be sheared up to 50% once vigorous new
shoot form in April. Late summer or Autumn blooming types can be sheared
to 1 foot from the ground in February or March.
CLETHRA Summersweet blooms on new growth. Rejuvenate or renew annually
in March. Or remove stems more than 5 years old by rejuvenation.
CORNUS Dogwood bushes. Rejuvenate or renew annually. The younger twigs
or stems are the brightest colored. Remove stems more than 5 years old
by rejuvenation. Gradual production of a stool yields the finest form.
Pagoda dogwood. Only health, structure or deep prune in March. Allow an
occasional shoot to mature. If it is maintained as a single trunk, the
entire trunk will ultimately die as each trunk generally persists for
less than 15 years. You must allow for new trunks to develop and replace
the older ones when the time arrives.
COTINUS Smoke bushes flower on old wood. Health prune post flowering.
The best foliage is produced on new growth. Encourage a coppice growth
structure on the bush forms.
COTONEASTER Health prune in March. Deep prune longest or oldest branches.
Tree types should only be health pruned in March or immediately post flowering.
DAPHNE Daphnes are only health pruned when necessary. If they become too
large shearing 10-20% annually post flowering is acceptable but rarely
desirable.
EUONYMUS Burning Bush can be deep pruned up to 50% in March. Tolerates
shearing quite well.
EUONYMUS Wintercreeper. Ruthless shearing is occasionally required.
HAMAMELIS Witchhazel should be health pruned only and then between flowering
and leaf formation.
HIBISCUS Rose of Sharon. Prune back by up to 50% of the height in March
as they bloom on new wood.
HYDRANGEA Panicled types should be health pruned only. Anna Bell hydrangea
should be renewed every March. Oak-leaf hydrangea is shaped by 10-20%
post flowering and occasionally rejuvenated or renewed every 5-10 years
in March. Big leaf hydrangea should be deadheaded in late March with health
pruning to vigorous shoots in April-May. Climbing hydrangea is only dead
headed and health pruned in March.
JUNIPERUS Trees and dwarf types are best health or deep pruned in Late
Winter.
KERRIA Japanese Kerria is rejuvenated or renewal pruned every few years
post flowering.
LAVANDULA Lavender is sheared 30-50% once growth appears in the spring.
LONICERA Non-native Honeysuckle bushes should be ruthlessly removed.
.
MAHONIA Oregongrapeholly is health pruned once vigorous growth appears
in the spring or immediately post flowering.
MALUS Crabapples are pruned for health, epicormics, suckers and crossings
in March or immediately post flowering.
PAEONIA Tree peonies are health pruned once healthy growth appears in
the spring.
PICEA Spruce. Dwarf types are decandled when shoots have matured 50%.
Health or deep prune trees in Late Winter.
PINUS Pines. Dwarf types are decandled when shoots have matured 50%. Health
or deep prune trees in Late Winter.
POTENTILLA Renewal prune every 3-5 years. Shear back by 30 to 50% every
March.
RHAMNUS Non-native Buckthorns should be ruthlessly removed.
RIBES Currants can be sheared up to 80% in March or renewed annually.
SALIX Bush types such as Blue Arctic should be sheared up to 80% in March
or rejuvenated or renewed annually. Coppice pruning beautifully enhances
the form. Trees should be health pruned and check for narrow crotches
and bark inclusions in March.
SORBARIA False Ural Spiraea is rejuvenated or renewed annually in March.
SPIRAEA Summer blooming types respond wonderfully to renewal pruning in
March. Spring blooming forms should be rejuvenated annually or renewal
pruned post flowering when they become overgrown. Shearing summer blooming
types post flowering often results in a second flowering season.
SYMPHORICARPOS Coral Berry is renewed annually or every 3 years or so
in March.
SYRINGA Lilacs are rejuvenated post flowering when they become overgrown.
Tree types should only be health pruned. Small bush types can be renewal
pruned post flowering.
TAXUS Yews are health or deep pruned in Late Winter or following evidence
of flush in late spring. They are quite tolerant of shearing about 10%
post flushing
.
THUJA Arborvitae can be sheared by 10% or deep pruned to retain natural
look and shape. Prune in Late Winter.
TSUGA Hemlocks are health or deep pruned in Late Winter. Shear 10% post
flushing.
VIBURNUM Rejuvenate annually or renew prune to 6” – 12”
post flowering when the shrub types become overgrown. Tree types should
be health pruned.
COPYRIGHT ” February 11, 1998 Landscape Designs, Inc. Steve Lesch
Revised 11 28, 1999. Revised 3/19/03
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