Colorado's Premier Company For

Plant Health Care in Colorado

Splintered Forest

Plant Health Care Services

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Here at Splintered Forest, we love trees and the outdoors and we know you do too!

Taking care of your trees doesn’t stop at just watering and pruning. If your tree still seems to be declining even with routine care there might be another factor at play.

At Splintered Forest we have ISA Certified Arborists on staff as well as Qualified Supervisors who are licensed through the Department of Agriculture to advise you about plant health care options and to provide the necessary applications.

We understand that each situation is unique and that a one-size-fits-all approach to tree care doesn’t work so we take the time to create an individual plan suited to your landscape. Let our team help you manage your trees, not just treat them. Learn more about Invasive Pests: EAB Emerald Ash Borer, Rocky Mountain Pine Beetle MPB, Tussock Moth, and Japanese Beetles.


Common Pests and Tree Diseases We Treat

  • Emerald Ash Borer
  • Tussock Moth
  • Mountain Pine Beetle
  • Ips Beetle
  • Honeylocust Canker

Signs To Look For

A tree that is showing signs of stress may have a pest or disease causing it to decline. Things to look for include:


Insect and Disease Management

Pest management starts with identifying the possible cause of your tree’s decline. By working with your arborist a plan can be made to control the pest and help your tree begin to recover.


Root and Soil Treatments

Some treatments are preventative. Things like fertilization and growth regulators can be used to better help your tree to fight off potential diseases and pests. By being proactive with your tree’s health you can help to minimize the chance of decline or death.

Fertilization: Soil composition can sometimes hinder your tree’s growth and affect its health. Fertilization can invigorate the soil with all the nutrients your tree needs to stay vibrant and healthy.

Growth Regulators: Growth regulators used in conjunction with pruning can extend the pruning cycle of your tree and keep it looking well groomed for longer (keep pruning costs down).

Tussock Moth

Douglas-fir tussock moth native species

Orgyia pseudotsugata, moths that defoliate Engelmann spruce, douglas-fir, true fir trees and sometimes blue spruce. Douglas fir is the preferred host. Defoliation doesn’t always cause death, but repeated infestations can cause trees to be weakened and to be susceptible to bark beetles. Signs of infestation are defoliated trees that begin at the top and progresses downwards. Improving tree health can help to mitigate the effects of infestations by improving ability to survive defoliation. Thinning out of host species and selecting for non host species may also help by limiting the amount of food for the larvae.  


Males can fly but females cannot. Males are active around mid-day and are gray-brown/dark brown with feathery antennae and about one inch in size. Peak activity is in July and August, but can continue later into the year. 

Treatments include pheromone trapping to trap males, chemical spraying to kill larval stage in the spring (although this is tricky as the top of the tree must be reached) and systemic insecticide injections that kill the larvae when they eat the needles. The benefits of injections are that the chemical is contained, lasts for two years and does not pose a threat to other wildlife.


Mountain pine beetle, Dendroctonus ponderosae, is .25 inches long and brown to black cylindrically-shaped. They are highly aggressive and can successfully colonize most species of pine including: lodgepole, ponderosa and limber pines. Damage is done when they tunnel through inner bark layers and harm the vascular tissue. The vascular tissue can also be infected by Blue Stain Fungi, a fungus that the beetles often carry spores of, which only speeds up the death of the tree by blocking water and sugar transport in the tree.


Signs of MPB include reddish pitch tubes where the adult has begun to bore into the tree followed by a vertical gallery under the bark where eggs have been laid. Management for MPB begins with thinning of stands of pine trees to keep their food source scarce and selecting for trees that are better able to slow or stop beetle infestation. The beetles can also be stopped by preventatively injecting an insecticide into the trunk that can prevent the beetle for up to two years. This can be paired with a fungicide to slow or prevent the spread of blue stain fungi throughout the tree.

IPS Beetle

Ips engraver beetles, Ips spp, are less than a quarter inch long, dark red-brown to black cylindrically shaped beetles. They attack all species of pines and some species of spruces. Signs include yellow to reddish-brown boring dust at entry sites or around the base of the tree. Y or H shaped galleries can be found under the bark where the adult has laid eggs. The larval stage then tunnels around the sapwood and causes dieback or discoloration in the upper parts of the tree. 


Keeping your trees healthy is a good way to help prevent Ips beetle infestation. Removal of green slash or spreading it to promote drying as the beetle is attracted to it. Trunk injections every two years can also help manage the beetle – it is best and most cost effective to only treat high value trees as the beetle does not rapidly kill trees like the mountain pine beetle

Spruce Beetle

Spruce beetle, Dendroctonus rufipennis, is dark brown to black with reddish brown wing covers and .25 inches long that rarely attacks below 9,000 feet.The beetle infests spruce trees with Engelmann spruce being its main host but will also attack blue spruces. They prefer downed spruce trees and trees larger than 16 inches in diameter and forests that are above 9,000 ft. Signs of infestation are yellow-green that fades to gray over a couple of years. Light reddish brown dust can be found around the tree from new borers entering and streams of resin flowing down the trunk that resembles candle wax.


The larval stage of the beetle tunnels through the vascular system of the tree disrupting its flow of nutrients/water and ultimately causes death. Maintaining overall tree and forest health can help to keep beetle numbers in check as well as making sure to remove downed spruce trees. Trunk injections can be used to prevent infestation for up to two years although this is recommended for trees that are high in value to keep costs low.

LILAC ASH BORER: native species

Lilac ash borer, Podosesia syringae, is a clearwing borer that attacks ash trees and lilacs. It looks like a wasp in the adult form, but is actually a moth and not harmful to humans. Damage from the larval stage causes tree decline and death in stressed trees while healthy, well established trees are usually not as likely to die. Exit holes are round and usually seen in the lower trunk of the tree and on lower limbs.


Treatments include proactive watering and nutrient additions to improve tree and shrub health. Trunk injections can also be used and may be beneficial as the chemical used protects against emerald ash borer as well.

EMERALD ASH BORER (EAB): invasive species

Emerald ash borer, Agrilus planipennis, is a flat-headed borer that attacks all true ash trees, this does not include mountain ash. It is emerald green in color and half an inch long. Infestations appear as defoliation in the upper canopy of the tree that progresses downwards as the larvae look for more vasculature to feed on. The larvae cause the most damage to the tree by cutting off transport of water and nutrients. Trees that are healthy and stressed are equally attacked by the beetle so improving tree health does little to stop progression of decline.


It may take years for the signs of decline to show, but with high infestation the beetle can kill a tree in two to four years. D shaped exit holes can be seen where the adults emerged and S-shaped galleries can be seen under bark of infected wood.

Management strategies for EAB include: replacement of host trees with non-host species and chemical treatment to kill the larvae. This can be done via trunk injection or soil treatment (the trunk injection is good for two years and has high effectiveness).


Growth regulators are chemicals that can be used to control growth of plants for 2-3 years. By changing the balance of hormones the tree focuses more energy into fibrous root growth rather than branch and stem growth. This allows for better nutrient and water uptake which in turn help mitigate tree stress from drought, nutrient deficiency or damage from pests or the environment. 


They can also be used to manage size for trees that are in confined spaces or that need to keep a certain size for aesthetic appeal.  The effect on canopy growth can be used to extend time between prunings, helping to reduce costs for homeowners and leading to a healthier tree. Growth regulators can be used also for treatments to help locust trees to compartmentalize canker diseases and slow their spread.

Splintered Forest Christopher Young

Christopher Young

Five Stars

Splintered Forest did a great job removing 2 very large trees in my backyard. They were very efficient and had the trees removed in 1/2 a day - which is probably due to the fact they had some amazing equipment (crane, trucks, etc.).

Splintered Forest Frazer Lockhart

Frazer Lockhart

Five Stars

This is a great company! ... They were quick to provide a clearly stated bid, then followed up with scheduling. When an opening occurred ahead of our scheduled date, they reached out to complete our job earlier. On-site they were professional and meticulous, working with high energy and real skill. It was a real pleasure to work with Splintered Forest. They are our new "go to" for any tree work.

Splintered Forest Kathleen Noonan

Kathleen Noonan

Five Stars

Splintered Forest was willing to work with our needs and were patient during the estimating process... The crews arrived on time every day, worked hard, and did a good job cleaning up the work areas at the end of each day.

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