9609 Leesburg Road Fort Wayne, IN 46818 (260) 625-3525
Soil moisture is gone! WATER NOW, AND WATER ALOT!
Treat all evergreen trees (pines, spruce, azalea, yews, etc.) with
sulpher to lower the pH. Freeze thaw helps to break it up.
Do
a fall fertilization. 12-12-12 works fine as do most - don't
over do it. Slow release fertilizers are probably better but cost
more.
When trees are moved with a tree spade, some roots are cut in the
process. This means that the tree has less of an ability to take
in water, and in turn needs help in this process.
When your new tree is first planted the root ball and hole need to be
completely saturated immediately. Beyond this, on the average, a
newly planted tree needs an inch of water per week. As a rule of
thumb the tree should only be allowed to dry out between waterings, and
never for an extended period of time.
Many people ask about fertilization. Fertilizer makes it harder
for a tree to take up water. For this reason it is better to
lightly fertilize and use rooting stimulants on newly planted
trees. It is also better to fertilize in the fall when the tree
is starting to shut down for the coming winter months and requires less
water. What to use? Sulfur is a good soil acidifier that
works for pines. In general, a good slow release fertilizer will
do the job for your new landscape.
Lots of material available at Ohio State's Web Site. Search on
trees once you are there. http://www.osu.edu
Conifers may be pruned any time of year, but pruning during the dormant
season may minimize sap and resin flow from cut branches.
Hardwood trees and shrubs without showy flowers: prune in the dormant
season to easily visualize the structure of the tree, to maximize wound
closure in the growing season after pruning, to reduce the chance of
transmitting disease, and to discourage excessive sap flow from wounds.
Recent wounds and the chemical scents they emit can actually attract
insects that spread tree disease. In particular, wounded elm wood is
known to attract bark beetles that harbor spores of the Dutch elm
disease fungus, and open wounds on oaks are known to attract beetles
that spread the oak wilt fungus. Take care to prune these trees during
the correct time of year to prevent spread of these fatal diseases.
Contact your local tree disease specialist to find out when to prune
these tree species in your area. Usually, the best time is during the
late fall and winter.
Flowering trees and shrubs: these should also be pruned during the
dormant season for the same reasons stated above; however, to preserve
the current year's flower crop, prune according to the following
schedule:
• Trees and shrubs that flower in early spring (redbud, dogwood, etc.)
should be pruned immediately after flowering (flower buds arise the
year before they flush, and will form on the new growth).
• Many flowering trees are susceptible to fireblight, a bacterial
disease that can be spread by pruning. These trees, including many
varieties of crabapple, hawthorn, pear, mountain ash, flowering quince
and pyracantha, should be pruned during the dormant season. Check with
your county extension agent or a horticulturist for additional
information.
• Trees and shrubs that flower in the summer or fall always should be
pruned during the dormant season (flower buds will form on new twigs
during the next growing season, and the flowers will flush normally).
Dead branches: can be removed any time of the year.
Pruning Tools
Proper tools are essential for satisfactory pruning (Fig.6). The choice
of which tool to use depends largely on the size of branches to be
pruned and the amount of pruning to be done. If possible, test a tool
before you buy it to ensure it suits your specific needs. As with most
things, higher quality often equates to higher cost.
Generally speaking, the smaller a branch is when pruned, the sooner the
wound created will seal. Hand pruners are used to prune small branches
(under 2.5 cm diameter) and many different kinds are available. Hand
pruners can be grouped into by-pass or anvil styles based on the blade
configuration. Anvil style pruners have a straight blade that cuts the
branch against a small anvil or block as the handles are squeezed.
By-pass pruners use a curved cutting blade that slides past a broader
lower blade, much like a scissors. To prevent unnecessary tearing or
crushing of tissues, it is best to use a by-pass style pruner. Left- or
right-handed types can be purchased
.
Slightly larger branches that cannot be cut with a hand pruner may be
cut with small pruning saws (up to 10 cm) or lopping shears (up to 7 cm
diameter) with larger cutting surfaces and greater leverage. Lopping
shears are also available in by-pass and anvil styles.
For branches too large to be cut with a hand pruner or lopping shears,
pruning saws must be used. Pruning saws differ greatly in handle
styles, the length and shape of the blade, and the layout and type of
teeth. Most have tempered metal blades that retain their sharpness for
many pruning cuts. Unlike most other saws, pruning saws are often
designed to cut on the "pull-stroke."
Chain saws are preferred when pruning branches larger than about 10 cm.
Chainsaws should be used only by qualified individuals. To avoid the
need to cut branches greater than 10 cm diameter, prune when branches
are small.
Pole pruners must be used to cut branches beyond reach. Generally,
pruning heads can cut branches up to 4.4 cm diameter and are available
in the by-pass and anvil styles. Once again, the by-pass type is
preferred. For cutting larger branches, saw blades can be fastened
directly to the pruning head, or a separate saw head can be purchased.
Because of the danger of electrocution, pole pruners should not be used
near utility lines except by qualified utility line clearance
personnel.
To ensure that satisfactory cuts are made and to reduce fatigue, keep
your pruning tools sharp and in good working condition. Hand pruners,
lopping shears, and pole pruners should be periodically sharpened with
a sharpening stone. Replacement blades are available for many styles.
Pruning saws should be professionally sharpened or periodically
replaced. To reduce cost, many styles have replaceable blades.
Tools should be clean and sanitized as well as sharp. Although
sanitizing tools may be inconvenient and seldom practiced, doing so may
prevent the spread of disease from infected to healthy trees on
contaminated tools. Tools become contaminated when they come into
contact with fungi, bacteria, viruses and other microorganisms that
cause disease in trees. Most pathogens need some way of entering the
tree to cause disease, and fresh wounds are perfect places for
infections to begin. Microorganisms on tool surfaces are easily
introduced into susceptible trees when subsequent cuts are made. The
need for sanitizing tools can be greatly reduced by pruning during the
dormant season.
If sanitizing is necessary it should be practiced as follows: Before
each branch is cut, sanitize pruning tools with either 70% denatured
alcohol, or with liquid household bleach diluted 1 to 9 with water (1
part bleach, 9 parts water). Tools should be immersed in the solution,
preferably for 1-2 minutes, and wood particles should be wiped from all
cutting surfaces. Bleach is corrosive to metal surfaces, so tools
should be thoroughly cleaned with soap and water after each use.
Treating Wounds
Tree sap, gums, and resins are the natural means by which trees combat
invasion by pathogens. Although unsightly, sap flow from pruning wounds
is not generally harmful; however, excessive "bleeding" can weaken
trees.
When oaks or elms are wounded during a critical time of year (usually
spring for oaks, or throughout the growing season for elms) -- either
from storms, other unforeseen mechanical wounds, or from necessary
branch removals -- some type of wound dressing should be applied to the
wound. Do this immediately after the wound is created. In most other
instances, wound dressings are unnecessary, and may even be
detrimental. Wound dressings will not stop decay or cure infectious
diseases. They may actually interfere with the protective benefits of
tree gums and resins, and prevent wound surfaces from closing as
quickly as they might under natural conditions. The only benefit of
wound dressings is to prevent introduction of pathogens in the specific
cases of Dutch elm disease and oak wilt.
Pruning Guidelines
To encourage the development of a strong, healthy tree, consider the
following guidelines when pruning.
General
• Prune first for safety, next for health, and finally for aesthetics.
• Never prune trees that are touching or near utility lines; instead consult your local utility
company.
• Avoid pruning trees when you might increase susceptibility to
important pests (e.g. in areas where oak wilt exists, avoid pruning
oaks in the spring and early summer; prune trees susceptible to
fireblight only during the dormant season).
• Use the following decision guide for size of branches to be removed:
1. under 5 cm diameter - go ahead,
2. between 5 and 10 cm diameter - think twice, and
3. greater than 10 cm diameter - have a good reason.
Crown Thinning
• Assess how a tree will be pruned from the top down.
• Favor branches with strong, U-shaped angles of attachment. Remove
branches with weak, V-shaped angles of attachment and/or included bark.
• Ideally, lateral branches should be evenly spaced on the main stem of young trees.
• Remove any branches that rub or cross another branch.
• Make sure that lateral branches are no more than one-half to
three-quarters of the diameter of the stem to discourage the
development of co-dominant stems.
• Do not remove more than one- quarter of the living crown of a tree at
one time. If it is necessary to remove more, do it over successive
years.
Crown Raising
• Always maintain live branches on at least two-thirds of a tree's
total height. Removing too many lower branches will hinder the
development of a strong stem.
Remove basal sprouts and vigorous epicormic sprouts.
Crown Reduction
• Use crown reduction pruning only when absolutely necessary. Make the
pruning cut at a lateral branch that is at least one-third the diameter
of the stem to be removed.
• If it is necessary to remove more than half of the foliage from a
branch, remove the entire branch.
Glossary
Branch Axil: the angle formed where a branch joins another branch or stem of a woody plant.
Branch Bark Ridge:
a ridge of bark that forms in a branch crotch and partially around the
stem resulting from the growth of the stem and branch tissues against
one another.
Branch Collar:
a "shoulder" or bulge formed at the base of a branch by the annual
production of overlapping layers of branch and stem tissues.
Crown Raising:
a method of pruning to provide clearance for pedestrians, vehicles,
buildings, lines of sight, and vistas by removing lower branches.
Crown Reduction Pruning:
a method of pruning used to reduce the height of a tree. Branches are
cut back to laterals that are at least one-third the diameter of the
limb being removed.
Crown Thinning:
a method of pruning to increase light penetration and air movement
through the crown of a tree by selective removal of branches.
Callus: see woundwood.
Decurrent:
a major tree form resulting from weak apical control. Trees with this
form have several to many lateral branches that compete with the
central stem for dominance resulting in a spherical or globose crown.
Most hardwood trees have decurrent forms.
Epicormic Sprout:
a shoot that arises from latent or adventitious buds; also know as
water sprouts that occur for on stems and branches and suckers that are
produced from the base of trees. In older wood, epicormic shoots often
result from severe defoliation or radical pruning.
Excurrent:
a major tree form resulting from strong apical control. Trees with this
form have a strong central stem and pyramidal shape. Lateral branches
rarely compete for dominance. Most conifers and a few hardwoods, such
as sweetgum and tuliptree, have excurrent forms.
Flush Cuts: pruning cuts that originate inside the branch bark ridge or the branch collar, causing unnecessary injury to stem tissues.
Included Bark: bark enclosed between branches with narrow angles of attachment, forming a wedge between the branches.
Pollarding: the annual removal of all of the previous year's growth, resulting in a flush of slender shoots and branches each spring.
Stub Cuts: pruning cuts made too far outside the branch bark ridge or branch collar, that leave branch tissue attached to the stem.
Tipping:
a poor maintenance practice used to control the size of tree crowns;
involves the cutting of branches at right angles leaving long stubs.
Topping:
a poor maintenance practice often used to control the size of trees;
involves the indiscriminate cutting of branches and stems at right
angles leaving long stubs. Synonyms include rounding-over,
heading-back, dehorning, capping and hat-racking. Topping is often
improperly referred to as pollarding.
Topiary: the pruning and training of a plant into a desired geometric or animal shape.
Woundwood: lignified, differentiated tissues produced on woody plants as a response to wounding (also known as callus tissue).
References
ANSI Z133.1. 1994. Safety standards. American national standard for
tree care operators. Washington, DC: American National Standards
Institute.
ANSI A300. 1995. Standard practices for tree, shrub, and other woody
plant maintenance. Washington, DC: American National Standards
Institute.
Fazio, J. R. ed. 1992. Don't top trees. Tree City USA Bulletin No. 8.
Nebraska City, NE: The National Arbor Day Foundation.
Harris, R.W. 1994. Clarifying certain pruning terminology: thinning,
heading, pollarding. Journal of Arboriculture 20:50-54.
ISA Performance Guidelines Committee. 1994. Tree-pruning guidelines.
Savoy, IL: International Society of Arboriculture.
Ryan, H.D.P. III. 1994. Arboricultural pruning methodologies. Arborist News Volume 3(4):33-38.
Shigo, A. 1991. Modern arboriculture. Durham, NH: Shigo & Trees, Associates.
Shigo, A. 1989. Tree pruning: a worldwide photo guide. Durham, NH: Shigo & Trees, Associates.
Northeastern Area State and Private Forestry Offices
Headquarters
Northeastern Area State & Private Forestry
USDA Forest Service
100 Matsonford Road
5 Radnor Corporate Center, Suite 200
Radnor, PA 19087-4585 Durham Field Office
Northeastern Area State & Private Forestry
USDA Forest Service
Louis C. Wyman Forest Services Laboratory
P.O. Box 640
Durham, NH 03824-0640
Morgantown Field Office
Northeastern Area State & Private Forestry
USDA Forest Service
180 Canfield Street
Morgantown, WV 26505-3101 St. Paul Field Office
Northeastern Area State & Private Forestry
USDA Forest Service
1992 Folwell Avenue
St. Paul, MN 55108-1099
Authors
Peter J. Bedker, Plant Pathologist, USDA Forest Service, Northeastern Area State and Private Forestry
Joseph G. O'Brien, Plant Pathologist, USDA Forest Service, Northeastern Area State and Private Forestry
Manfred E. Mielke, Forest Health Specialist, USDA Forest Service, Northeastern Area State and Private Forestry
Illustrations by:
Julie Janke, Scientific Illustrator, Afton, Minnesota
Project Coordinator:
Gerard D. Hertel, Assistant Director, Forest Health and Management, USDA Forest Service, Northeastern Area State and Private Forestry
"How to Prune Trees" was written to help people properly prune the
trees they care about. If you doubt your ability to safely prune large
trees, please hire a professional arborist. Information in this
publication can be used to interview and hire a competent arborist.
|