Dutch Elm Disease | What is it and How Can You Control it?
Kerstin Kim January 3, 2024

American elm trees are native to North America, and they can grow to magnificent heights and live for centuries. Unfortunately, they’re susceptible to a devastating disease known as Dutch elm disease, or DED, that can quickly spread and devastate large areas where healthy elms grow. So, what is Dutch elm disease, and how can you prevent it from spreading to your health Denver trees? Our arborists at American Arbor Care are committed to keeping our Colorado elms healthy and strong.

What is Dutch Elm Disease?

Dutch elm disease is caused by a fungus that is spread by elm bark beetles. These tiny pests carry the spores of a fungal pathogen called Ophiostoma novo-ulmi. When an elm bark beetle burrows tunnels through the bark of an American elm tree, it leaves spores behind which quickly infect the tree. DED can infect all species of elms that are native to North America, but American elms are the most susceptible to the fungus. Once a tree has been infected, it quickly deteriorates and dies within three years.

A Brief History of Dutch Elm Disease in Colorado

Around 100 years ago, Denver city officials and local homeowners planted around 100,000 American elm trees throughout the city and state. In 1948, DED was first discovered in the state. Luckily, it died out and did not spread. In 1968, the disease reappeared and wreaked havoc on healthy elms in Denver, but it did not kill them all. Fortunately, Colorado did not have a case of DED for many years. This streak of luck ended in July of 2023, when the Denver City Forester confirmed DED along 17th Avenue in the South Park Hill neighborhood.

How Does Dutch Elm Disease Spread?

Dutch elm disease is a fungal disease that is spread by elm bark beetles. As the beetles fly from tree to tree, they carry spores and leave them behind on the as they burrow tunnels underneath the bark. Adult female elm bark beetles lay eggs under the bark of healthy elm trees, and when they emerge as adults, new beetles are released to infect more trees in the area. It’s a fast-spreading fungal disease that is hard to spot, and infected trees must be treated preventatively in order to be saved.

What Are the Symptoms of Dutch Elm Disease?

Symptoms of DED include:

  • Discolored leaves
  • Wilting leaves and branches
  • Upper canopy leaves that begin to die and turn brown
  • Fallen leaves in the spring and summer
  • Brown streaking along the sapwood (located underneath the bark of infected branches)

As the disease progresses, branches will begin to die and the tree will quickly decline. An untreated tree with DED will die within two to three years of infection. If you suspect that your tree has been infected, it’s crucial to have an arborist check it out as soon as possible.

How to Save Your Elm Trees from Dutch Elm Disease

There is no cure for DED, but there are preventative treatments to keep it away, and successful treatments to keep the infection at bay. When an elm tree is diagnosed with DED, infected branches must be removed and disposed of properly. This will slow the spread of the disease throughout the rest of the tree and to nearby elm trees. 

At American Arbor Care, we offer preventative trunk injections for healthy elm trees that will effectively prevent the spread of DED. This is the best and most effective treatment option to keep your elm trees from falling prey to DED. If you’d like to know more about DED and you’d like to have your elm trees treated for the disease, we’re happy to help. Contact American Arbor Care today.

Winter Time is the Best Time for Tree Removal: Here’s Why
Kerstin Kim January 9, 2024

Tree removal is a task that takes a lot of planning and prep, so it’s best to schedule it at the right time. Spring may be the best season to plant flowers and vegetables in your garden, but surprisingly, it’s not the best time to remove a tree. There are many advantages to scheduling tree removal in winter that are less invasive to the surrounding landscape. Let’s look at what makes winter the best time of year for tree removal.

The Benefits of Removing Trees in the Winter

Removing trees in the winter is a much easier process that causes less stress to the tree and surrounding landscape. Although it may be a chilly job, the process will go much smoother than if it was scheduled for a warm, summer day. One added perk is, most pests and diseases are also dormant in winter, which lessens the risk of them spreading as the tree is effectively removed.

Trees are Easier to Access

Most trees in winter are completely bare, and all the leaves have fallen to the ground. This makes it much easier to access the many branches for removal. Fewer leaves means less mess, better access to proper cuts, and fewer loads of debris.

It Causes Less Damage to the Surrounding Landscape

When the ground is frozen in winter, it’s less likely to be damaged and disturbed by the crew’s tree removal equipment. Heavy branches and heavy equipment can tear up the tender summer soil, but in winter, they are far less likely to leave a mark.

How is Tree Removal Less Invasive in the Winter?

Winter is the prime time for tree removal for a number of reasons. It’s less invasive because:

  • plants and vegetation are dormant, which means they’re less likely to sustain damage from the crew’s tree removal equipment.
  • soil is typically frozen, which means it’s less likely to erode when the tree is removed.

Although most people schedule landscaping tasks for spring and summer months, tree removal really is best in the winter. That’s because it’s a time when plants and trees go dormant and the soil stays nice and frozen, right where it’s at. You won’t be sorry for scheduling tree removal in the winter.

Trust American Arbor Care With Your Tree Removal

Removing trees requires extensive knowledge, professional crews, and a lot of heavy equipment. Although it can be scheduled year-round, tree removal is best performed in the winter months. By scheduling a winter tree removal service, you can rest assured that your landscape won’t be harmed and potential diseases won’t spread. If you’re interested in having a tree removed from your property, your first step is to get an estimate from a certified arborist. At American Arbor Care, we’re equipped with the best crews, the best equipment, and the most experienced personnel in the Denver area. Contact us today to schedule a free estimate for winter tree removal.

The Importance of Pruning Young Trees and How it Can Prevent Storm Damage
Kerstin Kim January 9, 2024

Pruning young trees may seem counterproductive, but it’s essential to healthy growth. Let’s look at why pruning is so important, how you can do it properly, and how pruning can prevent your young trees from being susceptible to storm damage. Our arborists at American Arbor Care are experts at properly pruning trees and ensuring that they grow healthy and strong.

The Benefits of Pruning Young Trees

Pruning a young tree helps it to be upright and strong over the course of its (hopefully very) long life. By pruning away unneeded branches, you can create a strong base and structure that focuses new growth in all the right places. By pruning your young tree, its canopy isn’t just more aesthetically pleasing, it’s also more balanced, which ensures a stronger trunk and root structure beneath.

Diseased and damaged branches can affect the health of the entire tree. By pruning them away, you’re creating a healthier tree that can focus on new, healthy growth, without being weighed down by branches that are sick.

How to Prune Young Trees

Pruning young trees takes knowledge and skill, and it’s important to follow procedures to ensure that it stays healthy and strong.

  • Timing: The best time for pruning young trees is when they’re dormant. This is typically between late fall and winter. Dormancy means the tree is not actively growing, and it won’t be as affected by a few cuts here and there.
  • Tools: Use a sharp pair of pruning shears or a saw to prune your young tree.
  • Technique: Carefully cut branches at a 45-degree angle, just above a bud. Don’t make flush cuts or leave stubs. This can lead to open wounds that make a tree more susceptible to infestation and disease.

If you’re unsure about pruning your trees, contact your local arborist for advice, or to schedule a free inspection.

Specific Pruning Cuts For Young Trees

There are certain cuts that should be made when pruning young trees. 

  • Central Leader: This is what arborists call the trunk of your tree. Sometimes you have to pick a central leader early on and remove competing branches so it grows healthy, straight, and strong.
  • Scaffold Branches: These are the main branches that support the canopy of the entire tree. Make sure they’re evenly spaced around the trunk to support the canopy, and pick branches that are angled upward.
  • Lateral Branches: These smaller branches grow off of the scaffold branches. Trim and prune these branches to give your tree a balanced canopy and overall pleasing look. Damaged and diseased lateral branches should always be removed.

How to Prevent Storm Damage

All trees are susceptible to storm damage, but there are steps you can take to help your trees weather storms more effectively.

  1. Remove damaged and diseased branches. These branches are already weak and are most likely to break in a storm.
  2. Thin out the canopy. If it’s too dense, no more than a third the canopy can trap wind, which can lead to broken branches and extensive damage. A thinned canopy allows wind to pass through as a storm blows in.
  3. Raise the canopy to prevent wind damage. Prune away lower branches to allow wind to pass below and through the branches with ease.

Trust American Arbor Care With Your Denver Trees

Pruning young trees is a great way to provide preventative care. By shaping and pruning your tree, you can encourage it to grow healthy, balanced, and strong. This ensures that your trees are better equipped to weather any storm that blows in. If you have questions about pruning young trees, or you’d like to get a free estimate from a local arborist, contact American Arbor Care today. We’d be happy to ensure that your trees are pruned effectively.

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