Is Your Tree Sick? Common Tree Diseases in Utah & What To Do

April 6, 2026
Uncategorized

You walk outside one morning and something looks off. The leaves on your maple are spotted and curling. Your pine has a section of brown needles that wasn’t there last fall. Your aspen’s bark has a dark, sunken wound that seems to be spreading. Something is wrong — but you’re not sure if it’s a big deal or just part of the season.

We hear versions of this story all the time. Homeowners across Salt Lake County, Sandy, and the surrounding valleys notice early warning signs but aren’t sure whether they’re looking at a serious tree disease, pest damage, or something less concerning. The trouble is, tree disease in Utah can move fast — and the difference between early treatment and full removal often comes down to how quickly you act.

In this guide, we’ll walk you through the most common tree diseases and health problems we see in Northern Utah, how to recognize them early, and what your real options are when something’s not right.

Signs of Fungal Infection: What to Look For on Utah Trees

Fungal disease is one of the most common tree health problems we encounter in Utah — and it’s particularly prevalent after wet springs or unusually humid stretches during summer. Our climate tends to run dry, which normally limits fungal spread, but when the conditions shift, fungi can move quickly through susceptible trees.

The most visible signs of fungal infection include:

Dark, water-soaked lesions or spots on leaves or bark
Powdery white or gray coating on leaf surfaces (powdery mildew)
Cankers — sunken, discolored areas on branches or the trunk where bark dies back
Premature leaf drop, often affecting just one side or section of the tree
Bracket or shelf fungi growing from the base or trunk (a serious sign)

Aspens are especially vulnerable to fungal problems in Utah. We regularly see cytospora canker in mature aspens — it causes the bark to darken and ooze, and it can girdle entire branches or sections of the trunk. If you have established aspens on your property and notice bark discoloration or unusual die-back, don’t wait to have them evaluated.

Cottonwoods and willows along irrigation canals and low-lying areas see frequent fungal issues as well, particularly where water pools around root zones after spring runoff.

“We got a call last summer from a homeowner in Cottonwood Heights whose aspen grove had developed dark, weeping patches on several trunks. By the time we evaluated the trees, two had active cytospora canker that had advanced significantly. We were able to treat and manage the others, but the two most affected trees ultimately needed removal. Catching it a season earlier likely would have changed that outcome.”

In many cases, targeted fungicide treatment and strategic pruning to improve airflow can slow or stop fungal spread — this is part of what we cover under our tree health care services. But the window for effective treatment narrows quickly, which is why professional evaluation matters.

Pest Damage: When Insects Are Killing Your Tree

Insects don’t just damage trees — some can kill them outright, and in Utah, we have several species that homeowners need to be aware of.

The biggest concern right now is the Emerald Ash Borer (EAB). This invasive beetle has been confirmed in Utah and poses a serious threat to the ash trees that are common throughout Salt Lake County and the Wasatch Front. EAB larvae bore beneath the bark and disrupt the tree’s vascular system, cutting off the flow of water and nutrients. By the time visible symptoms appear — sparse canopy, dieback from the crown down, S-shaped galleries under the bark — the infestation is often well advanced.

Other pests to watch for include:

Bark beetles — particularly in pines and spruces under drought stress; they leave small pitch tubes or sawdust-like frass at entry points
Spider mites — common during hot, dry Utah summers; they cause stippled, bronzed foliage, especially on junipers and ornamental trees
Aphids and scale insects — weakening trees over time, leaving sticky residue on leaves and surfaces below

One thing we emphasize to homeowners: pest damage and tree disease often occur together. A tree weakened by drought stress is more susceptible to bark beetles. A tree already fighting fungal disease becomes easier prey for opportunistic insects. When we evaluate a tree, we’re looking at the full picture — not just one problem in isolation.

If you have ash trees on your property and haven’t had them inspected recently, that should be a priority. Proactive EAB treatment is available and effective, but only if the tree is treated before the infestation becomes severe.

Needle Browning in Utah Pines: Disease, Drought, or Something Else?

Brown needles on a pine tree are one of the most common calls we receive — and also one of the most misunderstood symptoms. Not all needle browning means your tree is dying. But some of it absolutely does.

Here’s how to read the signs:

Normal seasonal needle drop: Pines shed older interior needles each fall — typically needles that are 2–3 years old. If the browning is happening on the interior of the tree and the tips of branches look green and healthy, this is likely normal.

Drought stress: Utah’s dry climate and periodic drought cycles hit pines hard, especially in newer developments where root systems haven’t fully established. Browning often starts at branch tips and progresses inward. Improving deep watering practices can make a significant difference.

Tip blight (Diplodia): This fungal disease causes new shoot growth to brown and die back, often with small black fruiting bodies visible at the base of needles. It’s common in stressed Austrian and Ponderosa pines across the Wasatch Front.

Bark beetle infestation: If browning is widespread and rapid — particularly in a tree that looked healthy just weeks ago — bark beetles may be the culprit. Look for small pitch tubes or reddish-brown boring dust around the trunk.

In mountain areas and the foothills above Salt Lake City, we also see pine needle scale and various needle cast diseases that can look similar. The point is that diagnosing needle browning correctly requires looking at the whole tree — age of affected needles, location of browning, condition of the bark, and the tree’s recent history.

When Treatment Works — and When Removal Is the Right Call

This is the question homeowners ask us most often, and we try to give a straight answer every time.

Treatment is the right path when:

The disease or pest problem is caught early, before structural integrity is compromised
Less than 30–40% of the canopy is affected
The root system and main trunk are healthy
The tree species responds well to available treatments (ash trees treated proactively for EAB, for example, have good outcomes)

Removal becomes necessary when:

Structural decay has compromised the trunk or major scaffold branches
Root rot has destabilized the tree — especially important to assess near homes, driveways, and fences
The disease has progressed beyond the point where treatment can meaningfully extend the tree’s life
The tree poses an active safety hazard, particularly heading into Utah’s winter storm season

We never recommend removal as the easy way out. Trees provide real value — shade, curb appeal, property value, and environmental benefits — and we work hard to find treatment options when they exist. But we also won’t tell a homeowner a tree is treatable when it isn’t. The goal is always the honest assessment.

“A homeowner in Sandy brought us in to look at a large cottonwood that had developed significant internal decay along the trunk. The canopy still looked reasonable, but when we assessed the structural integrity, the decay had progressed to a point where the tree was a genuine risk in a wind event. We recommended removal, helped them understand why, and they were grateful — a major branch came down in a storm that same fall.”

When removal is necessary, our tree removal service includes full cleanup — we leave the property the way we found it, minus the hazard.

What a Professional Tree Health Evaluation Looks Like in Salt Lake County

If you’re searching for an arborist near me or wondering whether your tree needs professional attention, here’s what to expect from a quality evaluation.

Our crews don’t just glance at a tree and give a quick answer. We walk the entire tree — from root zone to canopy. We look at:

Root flare and soil conditions (compaction, drainage, signs of root rot)
Bark integrity — checking for cankers, wounds, soft spots, and unusual discoloration
Structural assessment — branch architecture, included bark, any signs of internal decay
Canopy health — density, leaf color, signs of stress, pest activity
Recent history — drought stress, construction damage, soil disturbance

One thing that sets our crews apart is that any team member who shows up to your property can answer your questions confidently. You don’t need to wait for a specialist to follow up — we explain what we’re seeing, what it means, and what your options are, right then and there.

We also tell you what work is planned, when to expect us, and what the result will look like — because homeowners deserve to understand what’s happening with their own trees.

Our full tree health care services include disease diagnosis and treatment, targeted tree trimming to remove diseased or damaged wood, deep root fertilization, and preventive spraying programs. For trees that aren’t salvageable, we handle tree removal and stump grinding efficiently, leaving the property clean.

Red Flags: When to Call a Tree Professional Right Away

Some signs can wait for a scheduled consultation. Others shouldn’t. Call a professional promptly if you notice:

Sudden, widespread wilting or leaf drop during the growing season
Large cracks or splits in the main trunk or major limbs
Significant lean that has developed recently
Mushrooms or bracket fungi growing at the base or on the trunk
Dead branches over a home, roof, or high-traffic area
Signs of rapid pest infestation — pitch tubes, sawdust, or exit holes on the trunk
Any tree damage following a windstorm or heavy snow load

In Salt Lake County, we’re also heading into seasons where tree condition matters a lot. Summer heat and drought stress can push struggling trees over the edge, and early detection gives you options that simply won’t be available later.

Get Your Trees Evaluated by Rent A Monkey Tree Service

If something looks off with a tree on your property — or if you just want peace of mind before storm season — our crews are ready to help. We serve Sandy, Salt Lake City, Cottonwood Heights, South Jordan, and communities throughout Northern Utah.

Request a free tree health evaluation today. We’ll walk your property, give you a straight assessment, and explain all your options. No pressure, no upsell — just honest tree care from people who know Utah trees.

Request a Free Tree Health Evaluation