How to Care for Evergreen Trees in Denver

As Denver’s climate continues to change, evergreen trees are seeing an increase in pests and environmental stress. These pests can cause significant damage to evergreens if not treated regularly. In this blog post, we will discuss the most common pests that infest Denver’s evergreens, as well as the damage they can cause. We will also discuss some of the preventative measures you can take to keep your evergreens healthy and thriving!

Evergreen Trees In the Mile High City and Across the Front Range

Denver is home to a variety of evergreen tree species such as Douglas fir, Engelman spruce, and ponderosa pine. These trees are an important part of our city’s landscape and provide many benefits such as shade, oxygen production, and carbon sequestration. However, Denver’s evergreen trees are under threat from a variety of pests that can cause significant damage.

Pests That Prey On Evergreens in Colorado

Two of the most common pests that target evergreen trees in Denver are the Ips beetle and the pine wilt nematode.

  • The Ips beetle is a small, wood-boring beetle that attacks a variety of evergreen trees including Douglas fir, Engelman spruce, and ponderosa pine. The Ips beetle feeds on the inner bark of trees, causing them to slowly starve to death.
  • The pine wilt nematode is a microscopic worm that attacks the vascular system of evergreen trees, preventing them from transporting water and nutrients throughout their bodies. This results in the tree’s needles turning brown and eventually dying.

Both of these pests are native to Colorado and can be found in many Denver evergreen trees. Pests typically emerge in late spring and early summer, causing significant damage to evergreen trees before they are even noticed.

To prevent these pests from harming your Denver evergreen trees, it is important to regularly inspect them for signs of infestation and stress. If you notice any browning needles or branches, call one of our certified arborists to investigate!

Here are some tips for doing routine checks of your evergreens on your own:

  • Look for any browning needles or branches
  • Check for signs of chewing or other damage to the bark
  • Inspect the tree’s roots for any unusual growth
  • Ips beetles are small and brown, about the size of a grain of rice
  • Pine wilt nematode is too small to see with the naked eye, but look for symptoms like: sudden wilting or dying of branches,  yellowing needles, resin oozing from the trunk or branches

If you notice anything suspicious, call a certified arborist right away! If you think your Denver evergreen tree may be infested with a pest, there’s no time to waste. They will be able to properly diagnose the problem and recommend a course of treatment.

Evergreen Trees Are Sustaining Serious Damage

You may be wondering, how serious is a pest infestation? The truth is, these insects can deal serious damage to your Denver Evergreens. For example, Ips beetles tunnel through the bark of trees, causing them to slowly bleed to death. This “sapwood staining” is a sure sign that your evergreen is infested with Ips.

The microscopic Pine wilt nematodes worms invade the evergreen through open wounds in the bark. The nematodes travel up to the needles where they block the flow of water and nutrients, causing the tree to wilt and eventually die.

Trees that are already under stress from drought, poor nutrition, physical damage, extreme temperatures, and poor air quality all contribute to tree stress and make trees more susceptible to these pests. This is why it’s so important to take proper care of your trees year-round. Strong and healthy trees are more resilient and have the ability to fight off infestation.

Regular Tree Maintenance For Denver Evergreens

Proper tree maintenance is key to preventing pests from damaging Denver evergreen trees. Routine trunk injections and soil drenching can help Denver evergreens stay healthy and strong, making them more resistant to pests. Denver evergreen trees should also be pruned regularly to remove dead or dying branches that could provide a foothold for pests.

By following these simple steps, you can help keep Denver’s evergreen population healthy and prevent further environmental damage.

Trunk Injections

Many homeowners have never heard of trunk injections, which is normal because it’s above and beyond basic plant care. Trunk injections are a preventative measure that helps Denver evergreens stay healthy by delivering nutrients directly to the tree’s vascular system.

The trunk injection process consists of drilling small holes into the tree trunk and injecting a nutrient-rich solution directly into the tree. This method bypasses the tree’s leaves, which can often be damaged or diseased, and ensures that the nutrients go straight to where they’re needed most – the roots.

This is not a DIY task. Trunk injections should be performed by a certified arborist to ensure that the injection process is done correctly and doesn’t damage the tree. The thing about trunk injections is that they are highly effective, provide 2 years of protection and help prevent the spread of pests.

Soil Drenching

In addition to trunk injections, Denver evergreen trees should also be given a soil drench every few years. A soil drench is simply a process of applying water and nutrients directly to the tree’s roots.

This can be done with a hose-end sprayer or by hiring a professional arborist. Soil drenching is effective because it helps the tree absorb nutrients and moisture more efficiently. Denver evergreens need all the help they can get when it comes to absorbing nutrients and moisture!

Denver evergreens need to be watered deeply and regularly during the summer months to prevent drought stress, which makes them more susceptible to pests and diseases. You’d be amazed what proper watering and proactive support can do for your Evergreens’ health!


Mulching is another important step in Denver’s evergreen tree care. Mulch helps retain moisture, prevents weed growth, and insulates roots from extreme temperatures. When applying mulch, be sure to keep it away from the tree trunk to prevent rot. A general rule of thumb is to apply mulch in a ring that is two to three times the diameter of the tree’s canopy.

Proper Fertilization

Fertilizing Denver evergreens is important to maintain their health, but it’s important not to overdo it. Evergreens are susceptible to fertilizer burn, which can cause browning of the needles. It is best to fertilize evergreens in early spring before new growth begins. When applying fertilizer, be sure to follow the manufacturer’s instructions and water the tree well afterward.

Team Up With Our Experienced Arborists

Keeping your trees and plants safe from infestation and disease can feel like a full-time job! Luckily, you don’t have to tackle this task alone. Our team of certified arborists at Fielding Tree & Shrub Care are here to help. We have years of experience caring for Denver’s trees and plants, and we’re dedicated to providing the best possible service.

Here are some of the benefits of hiring a professional arborist:

  • Save time: Caring for your trees and plants can be time-consuming. Hiring a professional arborist frees up your time so you can focus on other things.
  • Save money: Professional arborists have the knowledge and experience to quickly identify and solve problems. This can save you money in the long run by preventing wasting money and effort on ineffective practices.
  • Save trees: A healthy tree can live for generations, providing beauty, shade, and habitat for wildlife. A professional arborist can help you keep your trees healthy and prevent them from being damaged or killed by pests, diseases, or poor care.

Invest In a Plan That Works

Everyone has a certain budget for their tree and lawn care, and you want to make sure that your money is well-spent. That’s why it’s important to do your homework and find a tree care company that has a solid reputation and offers a comprehensive plan that meets your needs.

Our team believes that your trees and shrubs deserve a comprehensive tree maintenance plan customized to their exact needs and we have developed a tried and true approach to tree care.

Step 1: Onsite Assessment

A certified arborist will perform a comprehensive on-site examination of your property. During the consultation, we identify:

  • each species of tree and shrub
  • signs of infestation, damage, and disease
  • each tree’s condition and specific needs
  • the time of year that will yield the best results for treatment

Our experts will prioritize which trees and shrubs can add the greatest value to your property. You’ll receive a comprehensive, customized assessment, including a proposed treatment and maintenance plan.

Step 2: Implement Treatment Plan

We will coordinate the scheduling of your services based on your specific tree and shrubs’ needs, time of year, and your availability. Our crew of licensed, insured arborists implement your maintenance plan to get your trees and shrubs looking their best.

Step 3: Ongoing Tree Maintenance

Long-term care for trees and shrubs, not a one-and-done treatment is the best approach. Ongoing tree maintenance includes continuing to protect your trees from pests and disease, annual fertilization, and complimentary consultations.

Help your Evergreens stay strong and healthy.  Contact our expert arborists today for a consultation!