What Does an Arborist Do and When Should You Call One?

An arborist is a professional who specializes in the care and management of trees. Arboriculture focuses on individual trees and woody plants rather than forests as a whole.

An arborist may work with:

• tree health
• pruning
• structural problems
• insects
• disease
• roots
• soil conditions
• storm damage
• tree preservation
• tree removal decisions
• planting
• risk concerns
• long-term tree management

The work is not simply cutting branches. A major part of arboriculture is understanding what a tree is doing, why it is doing it, and what action is appropriate.

ISA Certified Arborist is a professional credential administered by the International Society of Arboriculture. Certification requires applicants to meet experience or education requirements and pass an examination covering multiple areas of arboriculture.

Those areas include subjects such as:

• tree biology
• tree identification
• soil and water
• nutrition
• pruning
• diagnosis
• plant health care
• tree risk
• installation and establishment
• tree protection
• safe work practices

Certification does not mean every Certified Arborist will make the same recommendation. It does mean the arborist has demonstrated a defined level of arboricultural knowledge and is expected to maintain continuing education to keep the credential current.

Tree Pros has three ISA Certified Arborists on staff, and every crew leader is an ISA Certified Arborist.

A good tree evaluation goes beyond one symptom. An arborist may look at:

• tree species
• age and maturity
• canopy density
• leaf color
• dead branches
• branch attachments
• trunk condition
• bark
• cracks
• decay
• cavities
• roots
• root flare
• soil
• watering conditions
• construction history
• storm damage
• insect activity
• disease symptoms
• previous pruning
• nearby structures
• site use

The goal is to understand the entire tree and its growing environment. A single brown branch, insect hole, mushroom, or bark crack does not always tell the full story.

An arborist can evaluate visible structural conditions and help identify concerns that may affect the likelihood of tree or branch failure. That evaluation may include:

• dead branches
• weak branch attachments
• cracks
• decay
• cavities
• root damage
• changes in lean
• storm damage
• canopy imbalance
• previous failures
• surrounding targets

No tree can be guaranteed never to fail. Trees are living structures exposed to wind, snow, weather, insects, disease, and changing site conditions. The purpose of a professional evaluation is to identify observable concerns and determine reasonable management options.

Those options may include:

• monitoring
• pruning
• reducing a specific defect
• changing site use
• additional inspection
• or removal when appropriate

Sometimes. A tree that looks unhealthy may still have reasonable treatment or management options. The answer depends on what is causing the decline.

Possible causes include:

• drought
• root problems
• soil compaction
• nutrient issues
• insects
• disease
• storm damage
• construction injury
• poor planting
• previous pruning damage
• environmental stress

An arborist can help determine whether the underlying problem is manageable. Some trees may improve with appropriate care. Others may have extensive decline, structural damage, or decay that makes recovery unlikely. Diagnosis should come before assuming the tree needs treatment or removal.

No. Tree removal is one possible recommendation, but it should not be the automatic answer to every tree problem.

Depending on the tree, an arborist may recommend:

• no action
• monitoring
• pruning
• watering changes
• soil management
• plant health care
• insect management
• disease management
• structural support
• additional evaluation
• removal

At Tree Pros, if a tree can reasonably be preserved, we will say so. If removal is the practical option, we will explain why. A recommendation should fit the tree, not the service list.

A tree service may perform work such as pruning, removal, cleanup, or emergency response. An arborist brings specialized tree-care knowledge into the decision-making process.

The difference matters because the most important question is often not how to perform the work. It is whether the work should be done at all and what approach makes sense for the tree.

For example:

• Should this tree be removed?
• How much canopy should be pruned?
• Is this insect actually causing the decline?
• Does this tree need treatment?
• Is that branch structurally concerning?
• Can this storm-damaged tree recover?

An arborist helps answer those questions before the work begins. Tree Pros combines professional tree-care operations with arborist-led evaluation.

Board Certified Master Arborist is an advanced credential offered by the International Society of Arboriculture. It represents a higher level of professional knowledge and experience within arboriculture.

Tree Pros founder Paul Goin became an ISA Certified Arborist in 1988 and earned the ISA Board Certified Master Arborist credential in 2015. Paul also holds ISA Tree Risk Assessment Qualification and is an ASCA Academy Graduate.

Tree risk evaluation considers both the tree and what surrounds it. An arborist may evaluate:

• structural defects
• dead branches
• decay
• cracks
• root condition
• lean
• branch attachments
• previous failures
• storm damage
• tree health
• likelihood of failure
• what could be affected if failure occurs

A large dead branch over an unused part of a property may present a different situation from the same branch over a driveway, sidewalk, patio, or home. Risk is not based on the tree alone. Location and property use matter too.

An arborist evaluation is especially useful when there is a decision to make. Examples include:

• whether to remove a tree
• whether storm damage can be repaired
• whether pruning is necessary
• whether an insect problem needs treatment
• whether disease is present
• whether a declining tree can recover
• whether a mature tree should be preserved
• whether a structural defect needs action
• whether a tree is appropriate for a particular location

You do not need to wait until a tree is in severe decline. Early evaluation often provides more options than waiting until a problem becomes obvious.

Tree Pros has served the Denver metro since 2003, and founder Paul Goin has worked professionally in tree care since 1981. Our team includes three ISA Certified Arborists. Every crew leader is an ISA Certified Arborist. Paul Goin is an ISA Board Certified Master Arborist and holds ISA Tree Risk Assessment Qualification.

That experience helps us approach tree care by starting with the condition of the tree rather than assuming which service it needs. We evaluate first. Then we explain what we see, what the reasonable options are, and what we recommend.

Sometimes that means pruning. Sometimes treatment. Sometimes monitoring. Sometimes removal. And sometimes the right answer is to leave the tree alone.