The Lifecycle of the Emerald Ash Borer – a Video

Check out this great Emerald Ash Borer lifecycle video produced by the Minnesota Department of Agriculture. This quickly shows how this pest can be spread through transported firewood, and then how it infests and destroys Ash trees.

This video was produced by MDA through a unique collaboration with faculty and students of Art Institutes International (Aii) and McNally Smith College of Music. The collaboration began back in October 2009 when an MDA staff member contacted Shannon Gilley, a faculty member and 3-D digital artist at Aii. Gilley and his students began creating rough sketches based on the concept Cycle of Destruction an idea that intended to show the entire life cycle of EAB while connecting its potential for killing ash trees.

After many sketches and a handful of revisions, the final draft was created in late March 2010 with assistance with sound design and soundtrack from McNally Smith College of Music faculty member Chris Cunningham and his students. This 30-second video is a unique specimen of technical communication in that it compresses a large amount of visual information into a small amount of time. The hopeful result is that viewers better understand the meaning behind the often-repeated message Dont Move Firewood in a way that reduces human-assisted movement of firewood that is one of the main ways that invasive species are spread.

This video was made with technical assistance from staff from the Minnesota Department of Agriculture, Minnesota Department of Natural Resources, and University of Minnesota Extension.

Production of this video was made possible with funding from the United States Department of Agriculture.

Learn more on our Emerald Ash Borer page »

Why prune trees in Winter in Denver

Pruning and trimming of trees is best done in the winter, as there are many reasons that it is more healthy for your trees in Denver.

Tree Trimmer in DenverWe are often asked “How do you know what to prune with trees are not leafed out?”

Here’s how our arborists know what to prune:

  • Dead branches will not have swollen (larger) buds, but will be dried out and a different color buds. They will also feel dry and are brittle when bent. Trained arborists can easily see the difference from their birds eye view when up in the tree.
  • Branch structure and defects are easier to see without the leaves.
  • Dead limbs are discolored, cracked, and dried out. Live limbs have a healthier, richer color tone.

Winter Tree Pruning advantages include:

  • Disease organisms such as Fireblight and Dutch Elm disease are not transmitted when trees are dormant making it a safer time to prune.
  • Flowers and bedding plants are less likely to be damaged.
  • Lawns are drier and harder which results in less damage.
  • Branches without leaves are lighter and easier to move.
  • Last, but not least – Mountain High Tree offers a 10% winter discount for tree pruning and tree removals  authorized to be done between December 1st and March 1st.

Denver Tree Trimming Service Deal




Denver Tree Removal

We had a large project in October to remove several trees from a Denver yard, what a  beautiful day for tree removals and what a view! Our expert Arborists used our new crane to handle this large tree removal job, which was an all day affair. Check out some of the photos from the day below… the last one is the view, wow!

Large Tree Removal in Denver with Crane Denver Tree Removal Company


Denver Tree Removal
Denver Tree Removal Denver Tree Removal Denver Tree Removal Company Denver Tree Removal Denver Tree Removal Company Denver Tree Removal Company Tree-Removal-Denver-3 Denver-Tree-Removal-Company-3 Tree-Removal-Company-in-Denver- Denver-Tree-Removal-3 Denver-Tree-Removal-4

Emerald Ash Borer University

As Arborists in Denver, Mountain High Tree staff members attend and participate in many ongoing education programs so that we’re on the cusp of what is going on in the tree service industry.

One of the biggest tree service topics today is the arrival of the Emerald Ash Borer in Boulder, Colorado in 2013. This devastating pest affects all types of Ash trees, and once it has infested a tree, the tree will perish. Ash trees do not have any resistance and must be protected, so the best course of action is prevention. If you have Ash trees in your Denver landscape, contact Mountain High Tree and we can come out and determine if your tree is in danger. We don’t recommend treatments for all trees, as the Ash Borer has not yet been found in Denver, but as the years go by, we will likely see the need to protect many Denver trees with tree trunk injection and soil treatments.

Emerald Ash Borer in DenverIf you are a tree-lover, and are interested in learning more about the Emerald Ash Borer, check out this Emerald Ash Borer University webpage from USDA Forest Service, Michigan State University, Purdue University and Ohio State University – the page features links and info for upcoming Emerald Ash Borer Webinars that go into great depth about the pest, it’s affect on trees, and the range and effectiveness of the various trunk injections and treatments that are being used. You can also view past webinars on this page:

Emerald Ash Borer in Denver - life cycle

The above screenshot shows the lifecycle of the Emerald Ash Borer, this image comes from the EAB Management Mythbusters Webinar from Oct 2014. To view this webinar, click on the “View Webinar” link on this page below:

We will keep you informed of all developments of the Emerald Ash Borer in Denver, we are all working together to find out solutions and the best methods of protection for our Ash trees to keep this pest at bay!

Learn more about this Denver tree pest on our Emerald Ash Borer page



Tree Pests in Denver – Boxelder Bugs

Denver Tree Pests - Boxelder BugBoxelder Bugs are a common pest in Denver that primarily feeds on female Boxelder Maple. Boxelder bugs rarely cause significant damage to trees.

This time of year we typically see them gathering in warm places around homes, such as south-facing brick walls. They gather in large numbers in the fall to seek a warm place to hibernate, often becoming a nuisance as they want to overwinter in protected places like your house! They do not really cause any damage other than that they can stain draperies or light-colored surfaces if squashed.

Most exterior insecticides are not that effective against boxelder bugs, if they are a nuisance we recommend to use a mix of laundry detergent and water, and spray it on the Boxelder bugs around your home if desired. If they come into the house, use a vacuum cleaner to vacuum them up, and make sure to seal off any cracks or gaps coming into your home to prevent them from getting inside.

In the spring the Boxelder bugs emerge from hibernation and feed on a variety of plants, but their preferred food is boxelder seed pods found on female Boxelder trees. The females lay eggs on leaves and stones and in the cracks and crevices in the bark of female Boxelder trees. The most permanent solution to the Boxelder bug problem is the removal of female Boxelder trees, though this is not usually desirable or practical.

If you have questions about your trees or pests, give our Arborists a call or send us an estimate request online here »


Winterizing Sprinkler Systems in Denver

Denver Sprinkler Winterization and Blow out

If it is expected to freeze and you haven’t winterized your sprinkler system yet, wrap towels or blankets around the exposed irrigation pipes, then cover with a plastic bag and secure in place with string or duct tape. This will help keep your pipes from freezing until properly blown out for the winter.

Preparing your Sprinkler System for Winter in Denver:

Preparing your sprinkler system for the winter must be done correctly to assure there are no costly repairs and replacements to make in the spring at system start-up. The process consists of expelling all the water from the irrigation system and equipment. This is necessary because water freezes in the irrigation system and will break pipes, fittings, valves, sprinklers, pumps, and other system components.

To minimize the risk of freeze damage, you’ll need to winterize your irrigation system. In areas where winterization is needed, irrigation systems are installed using one of three types of water removal; manual drain, auto drain, or blowout. If you don’t know your system type, it is best to use the blowout method.

Mountain High Tree, Lawn & Landscaping is in the process of scheduling sprinkler blowouts in October 2014. If you want us to come out and perform this service for you, please call our irrigation department at 303-457-5857 and ask for Elisha Harwood. We will drain the system, winterize the backflow device if your system is attached to domestic water, turn off the water supply, drain pumps, drain the PVB, and make sure all zones are properly blown out. You can also send us an estimate request online for sprinkler winterization.


Emerald Ash Borer Predator Introduced in Boulder, Colorado

Adult Emerald Ash Borer - Photo: Pennsylvania Dept. of Conservation and  Natural Resources - Forestry Archive •

Adult Emerald Ash Borer
Photo: Pennsylvania Dept. of Conservation and Natural Resources – Forestry Archive •

Emerald Ash Borer (EAB) is an exotic beetle that was discovered in southeastern Michigan in 2002. The adult beetles only nibble on ash foliage, causing little damage. The larvae are the problem – they feed on the inner bark of Ash trees, disrupting the tree’s ability to transport water and nutrients, resulting in the demise of tens of millions of Ash trees across the nation.

In September 2013, the City of Boulder Forestry staff discovered and confirmed that an Ash tree in northeast Boulder was killed by the Emerald Ash Borer. Since then, the Arborists and Forestry departments across the state have been working together to figure out solutions to this devastating pest.

Emerald Ash Borer attacks only Ash trees – there are an estimated 98,000 total Ash trees in Boulder, and Denver has an estimated 1.45 million Ash trees, and all of the susceptible   trees will die from EAB if not treated with pesticides or in someway protected.

The Colorado Department of Agriculture has announced that they are experimenting with a stingless parasitic wasp that preys on the Emerald Ash Borer. Read the article below regarding this interesting direction to help save our Ash trees in Colorado:

Emerald Ash Borer in Colorado

Tetrastichus planipennisi adult wasps will be released to see if they can help control the Emerald Ash Borer –Photo courtesy USDA – APHIS

EAB Predator Introduced 

According to a September 29, 2014 news release, from the Emerald Ash Borer Team with the Colorado Department of Agriculture a stingless parasitic wasp will be released in Boulder to assist in the control efforts directed at the emerald ash borer (EAB). EAB was discovered in Boulder in September of 2013. Here are some excerpts from that news release.

  • Over a thousand Tetrastichus planipennisi adult wasps will be released on the East Campus of the University of Colorado. Female wasps locate EAB larvae under ash bark and lay eggs in the larva. Eggs hatch in the larva and consume it before it can complete its life cycle.
  • The Colorado Department of Agriculture worked with the City of Boulder, the University of Colorado, and the USDA Agriculture Animal and Plant Health Inspection Service (APHIS) to acquire these wasps from the EAB Biological Control Production Facility located in Michigan.
  • This particular parasitic wasp is one of three parasites of EAB that were identified in China. EAB was introduced into the U.S. from China, most likely on wood packing material. EAB was positively identified in 2002, but not until it had become established in the native ash forests around Detroit, Michigan.
  • Following the initial release of wasps on September 29th, there could be two more wasp release events.
  •  The wasps focus on EAB larvae and are not attracted to people or pets.

Beneficial Insects 

In their native range all tree insect pests have one or more parasitic insects that will affect their population numbers. These beneficial insects have varying degrees of notoriety and effectiveness. One of the most famous predators is the lady beetle (aka – ladybug). The adults and larvae are voracious eaters of soft-bodied insects like aphids that feed on many plant types. The more common predators focus on garden insect pests with some crossover to tree insect pests. Here are other examples of predatory insects and their food source:

  • Green lacewing larvae; small caterpillars, beetles, aphids
  • Syrphid fly larvae; aphids
  • Mantids (aka – praying mantid); all insects

The Palisade Insectary,, operated by the Colorado Department of Agriculture, provides numerous insect pests of noxious weeds like tamarisk, leafy spurge, puncture vine, and spotted knapweed. These insects are effective in suppressing invasive weeds. However, most of the state’s citizens don’t know that the insectary has provided a biological control for the oriental fruit moth with the parasitic wasp Macrocentrus ancylivorus (aka Mac) since the 1940’s. Each year over a million wasps are released in western Colorado peach orchards to suppress the destructive oriental fruit moth.

Researchers are always on the lookout for bio control agents like predatory insects to control invasive pests. In the long run, bio control insects are cheaper than chemical pesticides, provide a safe to human health alternative, and are usually self-propagating. Adding beneficial insects to the pest control palette is always an environmentally effective technique, but it must always be accompanied with other IPM (Integrated Pest Management) efforts, as well as the promotion of tree diversity in the community forest. Planting and promoting tree diversity is a necessity for tomorrow’s urban forest.

Source: Tree E-News” October 2014 document from the Colorado State Forest Service.

Colorado Springs Arborist wins 3rd Place in Tree Climbing Championship

Colorado Springs Arborist

Kevin Kelley, Colorado Springs Arborist wins 3rd place!

We are proud to announce that our talented tree climber and Arborist from our Colorado Springs location, Kevin Kelly, took 3rd Place overall in the SA-RMC Tree Climbing Championship that was held on Saturday, Sept 27th. The competition events included Aerial Rescue, foot lock, belayed seed climb, throw line/setting an access line and work climb.Congrats to Kevin and all of the rest of Mountain High Tree’s climbing team – great work guys!! We’ll post more photos soon!

Denver Arborist

Here’s some words from Kevin about the event:
“One thing I would like to mention is the comradery during the competition. Every year without fail no matter the weather all the contestants, judges, techs and volunteers always have a great attitude and put in a wonderful effort towards the whole event. Everyone is chatting about each event and how well/terrible it went giving advice to one another. This is the main reason why I love this competition and look forward to it every year. There are several guys/gals there that I see once a year and each time we meet up its hugs and handshakes asking one another how their year has been. It is as if we had been in contact with each other the whole time.”
Colorado Springs Arborist“The events that take place during the preliminaries are: Aerial rescue, foot lock (49 feet), belayed seed climb, throw line/setting an access line and work climb. Each one is scored individually and the score/times are recorded, added up then posted on a board. Out of 41 people to compete the top 3 who have scored the total highest points over all in the preliminary events gets to go on and compete in the masters challenge later in the day. The masters challenge consists of doing a pre-climb inspection, setting an appropriate access line, ascending the tree and reach each individual stations, getting to the ground safely and pulling all your gear out of the tree before the time is up. The scoring is based off of time/innovation/techniques/safety and completion of each individual station.”

Colorado Springs Arborist“Luke Glines won it this year and will be representing the Rocky Mountain Chapter of the International Society of Arboriculture in Tampa Bay Florida this year to compete against all other chapter winners. This includes Europe, Australia, Canada and several other countries. Charly Wagner took second and I took third (three years in a row… I will get them one day).”
~ Kevin Kelly, Supervisor (13 years), ISA Certified Arborist

Does your tree need trimming in Colorado Springs or Denver? Contact us below:

Tree trimming in Colorado Springs: 719.444.8800 or click here »
Tree Trimming in Denver: 303.232.0666 or click here »


Denver Arborists – Tree Climbing Championship!

Denver Arborists - Tree Climbing

Come help us root for our Mountain High Tree Climbing Team at the SA-RMC Tree Climbing Championship on Saturday, September 27th from 7am-6pm at City Park, at 20th & York Street, just west of the Pavilion.

This should be a good time for all to watch all the expert tree climbers do their thing! Bring a picnic and enjoy the festivities while you watch the climbers in action. Good luck guys!


Tree Trimming

Tree trimming is very important to the long term health of your trees in Colorado. Tree trimming helps improve health and structure while reducing hazards and improving the appearance. Tree pruning is most often done in the winter months, when trees are dormant and structure is easy to see, and the possibility of spreading  disease is lowest. Plus, Mountain High Tree offers a 10% winter discount on tree trimming! Pruning this winter will help prevent tree limbs from breaking in spring snow storms, and will also help improve the health and beauty of your trees.

Our Arborists at Mountain High Tree are here to help keep your trees healthy. Never hesitate to contact us at 303.232.0666 send us an estimate request below to have one of our arborists evaluate your trees and recommend treatments.  Don’t worry, we don’t sell unnecessary services or try to up-sell you, so you can trust that we’ll recommend only what is best for your trees – because we LOVE trees!

Estimate Request