We will use the Triage Concept
Trē´-äzh Noun
A system designed to produce the
Making Proper (Sometimes Tough)
Tree Management Decisions
greatest benefit from limited treatment
facilities
Rex A. Bastian, Ph.D.
The Davey Tree Expert Co./The Care of Trees
Wheeling, IL
Triage
Triage vs. “Treeage”
Medical triage was developed
as a way to prioritize the
treatment of wounded soldiers
Typically identified three
groups:
» Green-Expected to survive
regardless of treatment
» Yellow-Can survive only with
the application of the best
treatment
» Black-Dead or not expected to
survive even with the
application of the best
treatment
Making Tough Tree Management Decisions
We can apply a similar concept to our work
» Based on presentation I heard given by Dr. Jim
Chatfield from the Ohio State University
– Modified with his permission
Only a small fraction of the insects in North
America are pests
» Of these, only a small fraction are serious
A similar situation holds with mites, fungi and
other microorganisms as well as abiotic factors
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In My Experience
I have seen:
“Treeage” Purpose
To evaluate the options available (or
» Arborists overemphasize or overestimate the
seriousness of a given situation
not available) for treatment
» Arborists implement programs that have little, if
any, chance for making an improvement in tree
health
To prioritize the need for response to a
Both set the stage for unhappy clients and a
negative impact upon the reputation of the
arborist, their company, and our industry
My Treeage Categories
Priority 1-Red
» An immediate threat to people or property exists
» Situation involves a “Regulatory Pest”
Priority 2-Yellow
» The plant will likely decline and die or be aesthetically
unacceptable unless appropriate action is taken
– This assumes that effective treatment options are available
Priority 3-Green
» The plant will likely survive whether or not treatments are applied
Priority 4-Black
» The plant is already dead or will not survive regardless of
treatment
Making Tough Tree Management Decisions
given landscape situation
To document the rationale of how work
should be prioritized
Priority 1-Red Example
Immediate Threat to People or Property
Typically involves high
risk trees
» Immediate intervention
warranted
» Removal of tree or limb is
recommended
» May have short and longer
term components
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Responsibility to Manage Risk
Identify
Evaluate
Recommend
options
Priority 1-Red Example
Serious Threat
Bring to attention of
homeowner/property
manager
» Their decision
Seek additional help
from a TRAQ qualified
arborist if necessary
Additional investigation
is often warranted
Priority 1-Red Example
Regulatory Pest
Emerald Ash Borer
» New County/Town
Asian Longhorn Beetle
Priority 2-Yellow Decline and/or die or unacceptable
appearance unless appropriate action is taken
Situation poses a serious threat to the plant
Both biotic and abiotic factors may be involved
Disease of Walnut
In some cases, there may be no appropriate
action available
All need to be reported to
Response time available may be short or long
Thousand Canker
your state Department of
Agriculture ASAP
» Containment, if possible, is
crucial
Making Tough Tree Management Decisions
» Depends upon the causal agent
Aesthetic considerations can “promote” a
Priority 3-Green pest to a Priority 2-Yellow pest
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Priority 2-Yellow Example
Insect
Priority 2-Yellow Example
Disease
Early Dutch elm disease
infection
Magnolia Scale
» Without treatment,
populations will
» Options available if caught
early
likely increase,
– Eradicative Pruning
resulting in death of
– Bark Tracing
twigs, branches, or
– Fungicide treatments?
» Response time critical
possibly the entire
Advanced infections
untreatable
tree
» Priority 4-Black
Priority 2-Yellow Example
Physical
Trees too deep in ground
» Often develop stem girdling
roots (SGRs) with time
– Can result in tree decline
and death beginning 10 to
15 years following
installation
» Crown excavations can ID
problem so that SGRs can be
removed
Other Priority 2-Yellow Concerns
(Considering Early Detection)
Insects
» Euonymus scale
» Bronze birch borer
» Bark Beetles
Diseases
Abiotic Issues
» Over/under watering
» Pines in heavy shade
» Chlorosis caused by
nutrient shortages
» Verticillium wilt
» Compacted soils
» Oak wilt (white oak group)
» Salt laden soils
» Sphaeropsis (Diplodia) tip
blight
» Apple scab
– Susceptible cultivars
during favorable weather
Making Tough Tree Management Decisions
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Priority 3-Green
The plant will likely survive whether or not treatments are applied
Problem poses no real health threat
Often looks worse than it is
Heavy Priority 3-Green situations for
successive years may push or develop
into Priority-2 Yellow situations
Disease
Sycamore Anthracnose
» Trees typically do well in
spite of heavy defoliation
year after year
– This doesn’t mean that
the disease has no
impact!
Making Tough Tree Management Decisions
Insect/Mite
Leaf Galls
» Pose no real
Does not mean that the concern is
unimportant
Priority 3-Green Example
Priority 3-Green Example
threat to the plant
» Even high
numbers result in
little, if any, injury
Priority 3-Green Example
Abiotic
Mild lawn care
herbicide injury
» Given time, trees
usually recover without
long term effects
Other types of
Aesthetic issues
herbicide can cause
Witches brooming of
twigs
severe damage
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Other Priority 3-Green Examples
Insects
» Most aphids
» Honeylocust plant
bug/leafhopper
» Twig girdlers/pruners
Diseases
Abiotic concerns
» Early/late freeze
injury
» Winter burn
» Burls or other benign
growths
Priority 4-Black
The plant is already dead or will not survive regardless of treatment
Need to know when it is time to, “Pull the Plug”
May not be the easiest thing to do
» Client pressure to “Save” their tree
» Client pressure to “Do Something”
» Not willing to accept your explanation
» Note: Being forced into “Doing Something” may get
» Many leaf spot
diseases
you into even more trouble down the road!
» Bacterial wetwood
– May indicate decay
Priority 4-Black
Insect
Advanced Pine
Engraver Beetle
» By time symptoms begin
to show, tree is basically
toast
– Blue stain fungus
– Vascular disruption
– Treatments expensive
and unlikely to work
Priority 4-Black
Disease
Oak Wilt (Red Oaks)
» Affected tree will
typically die over a one
to six week period
regardless of what you
try to do
» Nearby, asymptomatic
red oaks may be
considered Priority 2Yellow trees
Making Tough Tree Management Decisions
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Priority 4-Black
Abiotic
Other Priority 4-Black Examples
Insect
Abiotic
Severe Construction
» Advanced bronze birch borer
Injury
» Severe bark girdling
» Heavy euonymus scale
» Severe winter injury
» Peach borer on purple leaf
plum
» Severe stem girdling
roots
» Damage has already
been done
» Secondary pests will
often finish the job
Diseases
» Advanced DED
» Elm phloem necrosis
» Advanced Armillaria root rot
» Severe root injury
– Structural roots
» Severe chemical
injury
» Advanced bacterial leaf
scorch
Remember!
Categories and Pests/Conditions are not absolute
» DED can be either a Priority 2-yellow or Priority 4-Black
issue
– Depends on disease stage
A Priority 3-Green concern may still warrant
treatment
» Aesthetics
» Client attitude
Even though treatments are available, their use or
cost may not be justifiable
» Each client and situation is different
Making Tough Tree Management Decisions
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