Mature tree guide

Trees are Sacramento’s crowning glory. Anyone who
has strolled beneath the cooling, soothing canopy of
towering elms and sycamores knows the city is graced
by a special relationship with trees that dates back to
the city founders and civic leaders of the 1800’s. Our
region’s trees are continuously working to provide us
with benefits that range from beauty to energy savings,
increased property values and improved states of mind,
cleaner air and reduced risk of flood. They add interest
and character to our neighborhoods as they change with
the seasons, connecting us to the cycles of life and the
earth itself.
They provide homes and food for urban
wildlife. Beautiful trees make for happy people!
TREES
A REGIONAL RESOURCE
MATURE
Maintaining a mature tree increases your property value by
about 1%, saves you energy and water, and makes your
property more attractive and relaxing. But your tree also gives
a great deal to the community around it by reducing air
pollution and storm water runoff, cooling the air, and helping
to give your neighborhood its character. Keep your trees
healthy for yourself and your community!
The residents of Sacramento are uniquely positioned to benefit
from planting and maintaining trees. Most of Sacramento
County’s 6 million trees are private trees in yards and street
fronts. By providing regular care to keep trees healthy and
maximize their benefits, tree owners improve not only their
own property but keep Sacramento’s legacy of trees alive.
SCHEDULE TIME FOR YOUR TREES
Set up a regular schedule of simple maintenance if your tree is
established and older than 3 to 5 years. It is not difficult or
demanding. Regular care will ensure your trees will continue
to thrive and survive for generations. It will also help you avoid
expensive and dangerous situations caused by unhealthy trees.
An effective program includes regular inspection, watering,
pruning, mulching, and possible fertilization. You can do much
of the on-going tree care yourself, but at times a tree care
professional will be needed to diagnose problems and assist you
in solving them.
INSPECTION
Mature trees should be inspected on a regular basis, preferably
yearly. Do this safely from the ground, using binoculars if
necessary. Loss of vigor is the surest early warning sign there
may be a problem with your tree. Advice from an arborist
may be invaluable and a great yearly deposit on your long
term investment.
WHAT TO LOOK FOR
A healthy tree shows it! Here are some signs your tree is
growing well:
• Health and vigor – Tree species grow at different rates, so
make sure your tree is growing appropriately. Check for new
buds and leaves in spring, appropriate leaf size, twig growth,
and a full crown. Trees in good condition will have full crowns,
vigorous branch growth, and full sized leaves with good
coloring and condition.
• Structure – Most trees should have a strong upright central
leader with well attached, well spaced, balanced branches.
Pruning for structure should begin while the tree is young to
develop good form for future growth.
• Right Tree, Right Place – Know the size your tree will grow
and make sure it will not interfere with power lines,
infrastructure, or buildings.
WHAT TO LOOK OUT FOR
Regular inspection can prevent some tree failures, but not all
failures are predictable or preventable. If you suspect a problem
it is best to get a professional evaluation. Here are some
common warning signs.
LEANING
POTENTIAL
This mature oak should be inspected regularly to keep it in
the best condition.
Leaners result from sudden loss of root anchorage and are in
the process of falling over. Check your tree’s vertical position
and if roots are exposed on the opposite side of a lean. Leaners
are imminent hazards because they can fall at any time.
Inspect large branches for splits where they attach to your trees
and areas where many branches arise from the same point on a
trunk. Both indicate potentially hazardous and weak branches
and have a high chance for failure. Often these types of
branches will need to be removed.
PROBLEMS
WEAKLY ATTACHED BRANCHES
PROBLEMS
POTENTIAL
These codominant stems will grow to be a problem if not dealt with.
MULTIPLE TRUNKS
Also called codominant stems, these trunks are weakly attached
and prone to split apart.
CAVITIES AND EVIDENCE OF DECAY
Decay in pockets on branches, or in old wound cavities, and
mushrooms or conks on trunks or on roots at the base of your
tree may indicate hazardous conditions and potential structural
failure. An arborist should be called to evaluate your tree.
TRUNK AND BRANCH CRACKS
Cracks can be vertical or horizontal. Cracks in the bark are
typically not a problem; cracks into the wood are cause for
concern. An arborist should inspect your cracks to determine
depth and severity of damage. In some cases corrective pruning
can reduce potential hazards by lightening the load on the base
branch or trunk.
BROKEN BRANCHES
Broken branches or “hangers” are likely to fall without warning and
could cause serious damage. They should be removed immediately.
DEADWOOD
Branches that have died will eventually fall off. Small branches
usually should not cause concern, but dead branches larger
than 2" in diameter should be removed.
HOW TO CARE FOR YOUR TREE
WATERING
Deep water your trees to let the roots drink! The best way to
deep water trees is by a soaker hose that slowly applies water to
the soil over several hours or overnight. You can use a garden
hose set to a trickle and moved to at least four different
locations under the drip line. Sprinklers may be used to water
deeply by watering until water begins to run off, then waiting
at least an hour or two to resume watering. This should be
repeated until water has penetrated at least one foot in depth.
Special care will need to be taken when watering on a slope.
Water around and beyond the drip line of mature trees where
the roots are, not near the base of the trunk.
Irrigation frequency during our rainless months may vary greatly
depending on the tree species, daily temperatures, and location
in the yard, along with soil texture, structure and depth.
Established drought tolerant trees may need occasional
watering at one or two month intervals. California native oaks,
California laurel, cork oak, Chinese pistache and goldenrain
tree can be damaged and short lived with frequent summer
watering. Moisture adapted trees such as birches, redwoods,
magnolias and red maples may need regular deep watering
throughout their lives to look their best and perform well.
These and other species greatly benefit from an occasional deep
watering to the depth of at least a foot once or twice a month.
Trees in or near lawn areas with frequent shallow watering may
develop surface roots. Poorly adapted Monterey pine, Leyland
cypress and giant sequoia are prone to insect damage and
diseases in hot dry interior areas of the state regardless of how
much water they are given.
Use a shovel or soil sampling tube to check the depth of
moisture to at least a foot.
WATERING
Deep water your tree near the dripline and beyond.
MULCHING
MULCHING
Mulching is critical for young trees and helps develop a friendly
soil structure for tree roots. Cover the soil around your trees
four feet in diameter to a depth of four to six inches with
organic mulch or allow leaves or needles from the tree to
remain on the ground. Keep mulch 4"to 6" from the trunk of
the tree to prevent crown rot. As your tree canopy expands,
continue to expand the mulched area to cover the entire drip
line of your tree. Don’t mulch with stone cobbles, plastic, or
weed cloth – they create a hostile environment for root growth.
Mulching:
• Reduces competition from grass and weeds
• Improves movement of water and air through the soil
• Conserves moisture in the soil
• Protects tree roots from hot ground temperatures
• Provides plant nutrients and improves soil structure
for healthy root formation
• Protects trees from damage by lawn mowers, weed
cutters, herbicides and pesticides
• Conserves water
Native oaks mulch themselves with fallen leaves.
Mulch creates a friendly environment for tree roots.
FERTILIZING
Mature trees generally do not need fertilizer. Fertilizers are
not tree food, you do not “feed” a tree when you fertilize.
Tree food (sugar) is made by living leaves through the
process of photosynthesis.
Healthy leaves manufacture sugars (the tree food) which are
stored in healthy roots grown in healthy soil. Keeping the soil
within or beyond the dripline mulched helps create a perfect
environment for non-woody roots (these absorb essential
elements and water from the soil) and woody roots (these store
energy reserves and support the tree.
Warning - Many lawn fertilizers contain weed and feed
formulations and broadleaf herbicides that may be picked up
by tree roots and harm your trees if applied incorrectly.
FERTILIZING
If nutrient deficiencies are detected in a soil test, it may be
necessary to fertilize that soil to improve conditions and
ultimately, tree vigor. When considering supplemental fertilizer,
it is important to know when it should be applied, what
nutrients are needed, and how it should be applied. Fertilizer is
best applied in late summer or after the trees have completely
leafed out in spring. Consult your certified arborist or plant
care professional for advice on the best fertilizer for your trees
and the best application methods for each. Generally, nitrogen
can be broadcast and deep watered into the root zone.
Remember, mature trees have expansive actively growing root
systems that extend well beyond your tree’s dripline.
PRUNING
PRUNING
Done well, pruning can produce strong, healthy, attractive
trees. Prune only to your level of expertise – leave the larger
jobs to the pros! Correct pruning will help a tree maintain
safety, develop a strong structure, and enhance the vigor and
health of your tree. By creating a strong structure when your
tree is young, you’ve kept your tree vigorous and more able
to withstand damage from pests and natural forces such as
severe storms.
Since each pruning cut changes the growth of your tree and can
damage it, no branch should be removed without a reason.
Light pruning and removal of dead wood can be done at any
time. Heavier pruning should wait until your tree is dormant
in the late fall and winter.
Here are some tips to guide you in safe, correct pruning.
1. Most pruning that cannot be done from the ground or a
short ladder should be done by a competent arborist.
2. Do not stub tree branches. This is called heading or
topping. Instead use a thinning cut; remove the entire branch or
cut back to another branch that can assume the new lead.
Heading a tree causes several vigorous upright shoots to grow.
They are weakly attached and crowded, and the natural shape of
the tree is destroyed. Thinning retains a tree’s shape. Do not head
or “top” a tree to lower its height. Instead, prune by thinning or
crown reduction, but only as a last resort.
3. Do not make cuts flush to the trunk or branch.
• The small ridge or collar at the base of every branch protects
the tree from disease and insects. Cut just beyond this collar,
leaving it intact, but don’t leave a stub.
Good cuts will create wounds
that close well.
Make clean cuts outside of the
branch collar.
• Do not use a wound dressing on the pruning cuts. Pruning
cuts do not need wound paint or sealer. Trees seal themselves
by setting up a protective boundary between injured and
healthy tissue in a process known as compartmentalization of
decay. A good pruning cut will seal in a doughnut shape as
the branch collar closes around the wound. Wound dressings
may be detrimental as they will not stop decay and may
actually create a site for decay.
4. Prune for ideal structure with adequate branch spacing
to allow for sunlight and air movement and prevent insect
damage and disease.
• Remove any dead, diseased or crossing branches.
• Remove competing limbs and avoid one branch growing
directly over another.
• Space branches evenly around the tree in an ascending spiral.
Branches should be at least 8-12" apart on smaller and
younger trees and at least 18" apart for large growing trees.
• Select branches to keep with wide attachments of at least 45
degrees of attachment to the trunk. Narrow crotches are
weak and can split out. Keep side branches from outgrowing
the leader.
Small branches less than 1 inch in diameter can be cut using
by-pass hand shears or loppers. When directing growth, snip to
an outward growing bud, leaving no stub.
Larger branches greater than 1inch in diameter can be cut using
the 3-step cutting method using loppers or on larger sized
branches an appropriate pruning saw. The 3-step cut allows
removal of the weight of the limb before the final cut and
eliminates the possibility of ripping the bark down the trunk.
2. Cut outside the first cut all the way through the branch,
leaving a short stub.
3. Remove branch stub outside the branch collar. A proper
cut will not damage the branch collar.
PRUNING
1. Undercut with a shallow notch well outside the
branch collar.
PRUNING
LOPPERS
BY-PASS HAND SHEARS
Always keep pruning tools sharp and clean, in good working
condition. This will prolong their life and help you make clean,
accurate cuts without tearing your tree.
PRUNING TERMS
BRANCH COLLAR is the slightly swollen area where the
branch attaches to the trunk. When branches die or are
removed chemicals in the branch collar wall off or
compartmentalize wounds to prevent decay.
CROWN CLEANING refers to removing the deadwood,
broken or diseased branches, and “water sprouts.”
CROWN THINNING selectively reduces the density of the
top of the tree and opens the lower canopy to light and air
which benefits the inner leaves and can aid the health of the tree.
CROWN REDUCTION or drop crotching can temporarily
lower the height of a tree that has become taller than is
appropriate for the site. Cut back to a lateral branch that is at
least 1/3- 1/2 the diameter of the main branch.
CROWN RESTORATION is used to reshape a tree to give it
stronger structure and improved health. This technique is used
to correct improper pruning done in the past or to overcome
canopy damage.
NO TOPPING
Never top your tree! Topping is the practice of removing major
portions of a large tree’s crown by cutting branches to stubs or
to the trunk. Some homeowners think their tree is too big and
therefore, unsafe; some believe it is good for the health of the
tree; some simply planted the wrong tree in the wrong place
(under utility lines, for example) and need to “whack” it back
into its space. Tree topping shortens the life of your tree, creates
weakly attached limbs prone to breakage and disfigures your tree.
PRUNING
Topping shade trees can
cause serious damage to
your trees while creating
safety problems from the
resulting weakly
attached water sprouts.
NEVER top a tree.
PRUNING
HOW TO HIRE AN ARBORIST
Hire someone who is licensed, bonded, and insured. Examine
these credentials and feel free to check with the appropriate
agencies to verify the validity of the credentials. Remember
that almost anybody can obtain a business license, and that
alone is no guarantee of quality. Do ask for references and take
time to check them out.
Get more than one bid and examine the written specifications
of the bids. ASK QUESTIONS! If you are not familiar with
the terminology used, ask for clarification. Take your time
and select a company that is reputable. Determine the best
combination of price, work to be done, skill and professionalism
to protect your investment.
Membership in professional organizations demonstrates a
willingness on the part of the arborist to stay abreast of
arboricultural information. It is not a guarantee of satisfied
work, so check references.
Remember that improper tree care can take many years to
correct itself. If pruning is too severe, it may never be
corrected. A reliable arborist will try to talk you out of topping
a tree if it is requested. Never allow a climber to use spikes or
spurs to climb your tree unless it is scheduled for removal. Hire
an arborist as if your tree’s life depends on it!
Some jobs require a professional arborist.
COMMON DISEASE PROBLEMS for
SACRAMENTO AREA MATURE TREES
ANTHRACNOSE
Anthracnose is an airborne fungal disease that attacks new
shoots and leaves as they emerge in the humid air in spring.
Local tree species affected include Modesto Ash, California and
American sycamores, and London plane. The infection results
in leaf loss thus denying the tree the food from photosynthesis
and thereby weakening the tree. The fungal spores overwinter
in the fallen leaves and twigs. The disease can be controlled
with good sanitation practices: rake the fallen leaves and twigs
in when they drop, especially in the fall. Fungicides are
generally only effective on Modesto ash.
Mistletoe weakens the tree and makes it susceptible to other diseases.
MISTLETOE
DISEASE
Mistletoe is a parasitic infestation spread by birds carrying
seeds from tree to tree. It should be pruned yearly either by
removing infested tree limbs with thinning cuts or selective
removal from your tree. Mistletoe is a neighborhood problem
and if you remove mistletoe and your neighbors don’t it will
return sooner to your tree. Join together with your neighbors
and begin a comprehensive program to eliminate it from
your neighborhood.
OAK GALLS AND OAK WORMS
PROBLEMS
Both problems, while a nuisance, do not harm your oaks. Oak
worms last six weeks during some springs. There are no
effective controls for either.
PROBLEMS
FRUIT PRODUCTION
Birds and bees do not think of flowers and fruit as a problem.
But flowering trees planted too near sidewalks, patios, drive
ways and swimming pools can present landscape messes. An
arborist may be able to spray certain trees with a hormoneinhibiting spray to prevent fruit set. Timed correctly and
applied thoroughly, fruit production may be largely curtailed.
Sprays must be applied each year before fruit set.
DISEASE
DUTCH ELM DISEASE
DED is a fatal fungal infection that affects certain species of
elm trees. The best method of control is to remove infected
trees before the disease can be spread by bark beetles. If you
are interested in helping prevent the spread of the disease,
join the Save the Elms Program by calling the Sacramento
Tree Foundation.
Healthy trees fit into the urban environment.
Mature Tree Reference Guide
Sacramento Tree Foundation main office and
information on tree care classes and volunteer training
(916) 924-TREE • www.sactree.com
Stewardship Hotline – For tree care questions regarding
young shade trees planted through Tree Foundation
Programs – (800) 924- LEAF
SMUD Tree Division Line Clearance and Free Mulch –
(916) 732-5854
City of Sacramento Tree Services – (916) 433-6345
Sacramento County Tree Coordinator – (916) 874-5278
International Society of Arboriculture Western Chapter
ISA Office – (530) 892-1118
UC Cooperative Extension Master Gardeners –
(916) 875-6913
Roseville Urban Forest Foundation (916) 774-5666
Helpful Print Resources
Arboriculture: Integrated Management of Landscape
Trees, Shrubs, and Vines, Richard W. Harris, James R.
Clark, Nelda P. Matheny, Prentice Hall, 1999.
Pirone’s Tree Maintenance, John R. Hartman, Thomas P.
Pirone, Mary Ann Sall, Oxford University Press, 2000.
Modern Arboriculture: A Systems Approach To The Care
Of Trees And Their Associates, Alex L. Shigo, Shigo and
Trees, Asssociates, 1991.
Management Guide, Steve H. Dreistadt, Jack Kelly
Clark, Mary Louise Flint, University of California, 1994.
Sunset Western Garden Book, Kathleen Norris Brenzel,
Sunset Publishing, 2001.
RESOURCES
Pests of Landscape Trees and Shrubs: An Integrated Pest
The mission of the Sacramento Tree Foundation is to
promote the importance of trees and community
action in improving the quality of life and enhancing
the unique character of the Sacramento region.
Our vision is to work with the community to create a
legacy of trees for future generations.
OUR PROGRAMS INCLUDE:
• COMMUNITY SHADE
• MISTLETOE MANAGEMENT
• NEIGHBORWOODS
• NATURE
• SACRAMENTO NORTHERN RR PARKWAY
• SAVE THE ELMS (STEP)
• SEED TO SEEDLING
• REGIONAL URBAN FOREST STRATEGY
• COOL COMMUNITIES
• SHADE TREE PROGRAM