Insect & Disease Management in Denver
Denver’s Trees Are Under Pressure. We Can Help.
Denver’s semi-arid climate, periodic drought, and warming winters create conditions that invite insect infestations and disease. Stressed trees are vulnerable trees, and once a pest or pathogen takes hold, the window for effective treatment can close faster than most property owners expect.
This page covers the pest and disease threats most relevant to Front Range trees, how to spot early warning signs, and how Monster Tree Service of Southwest Denver approaches treatment and prevention.
If you’ve noticed something wrong with a tree on your property, don’t wait. Call us at (303) 622-5449 for a free, no-obligation evaluation.
Insects & Diseases That Threaten Denver Trees
Several pests and pathogens are active along the Front Range, and knowing which ones affect which species helps you act before damage becomes irreversible.
Emerald Ash Borer
Emerald ash borer is an invasive beetle that kills ash trees by destroying the tissue beneath the bark responsible for carrying water and nutrients. It was confirmed within Denver city limits on June 17, 2025, following a spread that began in Boulder in 2013 and moved through multiple Front Range communities. Without treatment, infested ash trees typically decline and die within two to four years.
Mountain Pine Beetle & Ips Beetles
Mountain pine beetle is native to Colorado and has caused widespread pine die-off across the state. Ips beetles, sometimes called engraver beetles, attack pines and spruces already weakened by drought or injury. Both are common threats in and around Denver, particularly at higher elevations toward Jefferson County and the foothills.
Dutch Elm Disease
Dutch elm disease is a fungal infection spread by elm bark beetles. A mature elm can die within a single growing season once the disease takes hold, making early detection critical for any property with established elms.
Fire Blight & Cytospora Canker
Fire blight is a bacterial disease that moves quickly through apple, pear, and crabapple trees, killing blossoms and twigs and leaving branches with a scorched appearance. Cytospora canker targets stressed spruce trees across the Front Range, causing branch dieback that worsens without intervention.
Emerald Ash Borer Treatment in Southwest Denver
Given the recent confirmation of emerald ash borer in Denver, ash tree owners should treat this as time-sensitive. Our certified arborists provide ash borer control services designed to address existing infestations and help protect treated trees from future attacks. We offer both trunk injections and soil injections, delivering systemic insecticide directly to the tree’s vascular system where it’s most effective. All treatment follows eco-friendly practices, and pricing is transparent and upfront. A professional assessment now can be far less costly than removal later.
Warning Signs a Tree Needs Professional Evaluation
Catching a problem early is an important factor in treatment. Watch for these signs:
Emerald ash borer indicators:
- D-shaped exit holes in the bark
- Thinning or dying canopy, often starting at the top
- Increased woodpecker activity concentrated on the trunk
Pine and spruce beetle indicators:
- Small pitch tubes (hardened resin masses) on the outer bark
- Fine sawdust or boring dust accumulating at the tree’s base
- Needles turning yellow-brown, starting mid-canopy
Disease indicators across species:
- Wilting or yellowing leaves starting on one side of the canopy (Dutch elm disease)
- Blackened, curled twigs resembling a shepherd’s crook (fire blight)
- Holes in leaves, sticky residue on branches, premature leaf drop, or discolored foliage
None of these signs are conclusive on their own, but any one of them is worth a closer look from a trained eye.
How We Approach Treatment & Prevention
We start with a professional inspection to identify what’s affecting a tree and how far the problem has progressed. Diagnosis drives treatment selection. We use state-of-the-art equipment, and every treatment plan follows environmentally responsible, industry-standard practices. The goal isn’t just to address an active problem but to support the long-term health of the tree, with attention to the safety of your family, pets, and the surrounding landscape.
Prevention matters just as much as treatment. A few practices make a meaningful difference for Front Range trees:
- Deep, infrequent watering helps trees resist the drought stress that makes them attractive targets for beetles and fungal disease
- Proper mulching around the root zone, kept away from the trunk’s base, reduces moisture extremes that invite pests and pathogens
- Prompt removal and disposal of infected wood limits the spread of disease-carrying insects to healthy trees nearby
Locally Owned, Licensed, & Insured
Monster Tree Service of Southwest Denver is locally owned and operated, which means we’re invested in the health of the trees on your property the same way you are. Our crews are fully licensed and insured, and all tree work follows ANSI Z133 safety standards. We show up on time, communicate clearly, and hold ourselves to a level of service that reflects what a local business owes its neighbors.
Schedule Your Free Tree Health Evaluation
If a tree on your property is showing symptoms, or if you want to know whether your ash trees are protected heading into the season, we’re ready to help. Every evaluation starts with a free, no-obligation estimate and fully transparent pricing with no hidden fees.
Call Monster Tree Service of Southwest Denver at (303) 622-5449 or schedule your appointment online.
