Mountain High Tree, Lawn, and Landscape Co.  October ‘06


What is Your Spruce Tree Doing?

Small black fruiting
bodies turned out
to be Sirococcus

The signs and
symptoms looked like Sirococcus, but these fruiting bodies were Leptosphaeria.

A fungus pretending to be Rhizosphaera! 

We've recently received numerous calls concerning discoloration in Colorado blue spruce. This is not an uncommon occurrence, as this is also the time for fall needle drop. To distinguish between normal fall needle drop and disease, examine where needle drop is occurring. New growth should not be affected.

However, some samples we examined are not normal fall needle drop. In Colorado, blue spruce grows faster than some other evergreen trees.  Common contributing factors in blue spruce death are two diseases: Rhizosphaera and Cytospora. However, the blue spruce samples that we've received this year often have multiple disease disorders in addition to Rhizosphaera and Cytospora!

The disease Rhizosphaera needle cast frequently infects Colorado blue spruce. Rhizosphaera needle cast is a fungal disease that infects the current year's needles. These needles later turn purple to brown and fall from the tree prematurely, leaving the inner portion of the branch bare. As the disease progresses, severely infected branches die; leaving the tree with a hollow or thin appearance. The disease starts near the base of the tree where humidity levels are the highest, but continues to spread upward. As the disease continues, trees become unsightly and lose their value as a visual screen or privacy fence. The Rhizosphaera pathogen, however, sporulates in the spring.

Colorado blue spruce is native to Colorado, but it often suffers from environmental stresses such as drought, excessive heat, and compacted soils. Spider mites were seen in association with almost all samples we've received. Apparently, Colorado blue spruce is more vulnerable to infection and more severely affected than white and Norway spruce to some native fungi. To minimize future problems, make sure your blue spruce are well watered and mulched going into this winter. It may be the difference between a healthy spruce and one that should be pruned at ground level!








Fall Needle Cast


Similar to the natural cycling of needles in Spruce is the common occurrence of interior needle drop in Pines.  Ponderosa Pines will cycle their needles every two to three years, thus producing a nearly annual load of brown needles.  This annual needle drop comes around every September and October.  The look of the brown needles is alarming at times, but it is important to look around at the trees of your neighbors and parks.  The important tissue to check is the newest material.  If the needles of this year and last year are intact then there is probably nothing to worry about.  But please note that if you are still concerned you can always call us or take a digital picture and email it to us.




Where Have All the Insects Gone


With fall descending upon us we feel the wind pick up and watch the leaves fly by.  Though insect activity drops off in the fall and comes to a standstill in the winter there is unseen activity that bears great importance to us. All insects spend their winter months in one form or another.  Several borers spend their winter nice and cozy under the bark of our trees, waiting for the right time to emerge.  Many other insects, such as mites, whitefly, aphids, and scale, over-winter in the egg stage of their life cycle.  Many of these insects have evolved to develop protective covering on their eggs to help insulate during the winter.  As our winters become more and more mild, the number of eggs exposed to low enough temperatures to have a substantial winter kill impact decreases.  It is imperative to step in and assist Mother Nature in controlling the number of insects that will hatch in the spring to inflict their damage. 


We have a few options available to treat over-wintering insect populations.  An application of horticultural oil in the fall or spring will coat eggs and deny the movement of gases through the egg covering.  This horticultural oil is also a “natural product” which allows us to decrease the amount of synthetic chemicals we release into the environment.  In addition to the oil,there is a synthetic chemical that works exclusively as an “ovicide”, which means egg killer.  This product is designed to work selectively on eggs and not on adults.  These products afford very good results in the spring when the decreased insect pressure on new plant material allows for healthy trees and shrubs. 


Contact one of our representative arborists if you would like more information. 








Winter Watering


The rainfall that temporarily graced us during later August and early September has abandoned us yet again.  Dry fall conditions damage tree roots through dessication, water loss, in the fine root hairs that are responsible for nutrient absorption.  When these roots dry up they die, and thus the potential for uptake is impacted.  The results manifest themselves in brown winter foliage, poor or no fall color, and branch dieback in the spring.  Undersized spring foliage can also result from insufficient winter soil moisture.  Due to low temperatures we will no doubt be turning off our irrigation systems very soon.  This adds to the depletion of soil moisture.  Applying a deep watering to the Critical Root Zone of your trees and shrubs when conditions warrant is an excellent way to ensure a good spring.  The Critical Root Zone is the area of soil where the highest percentage of fibrous roots exist. 


Contact one of our helpful arborist representatives to help you identify problem areas.



To Water or Not To Water, That is the Question


My apologies to Shakespeare for that obvious misuse of his famous quote but it is to make a point.


Fall is here with its beautiful colors and soon it will be time to shut down your sprinkler systems and forget about the lawn for a few months.  Well, that’s almost correct.  Depending on the temperature, wind and sun, our lawns and trees still need regular watering to get them ready for the long winter. So keep your sprinkler system running on a regular basis until it gets shut down for the season. Fall is the time of year that the lawn can repair damage done to it during the hot summer but it can’t do it without water.


November to April can be either really wet or very dry so here are a few tips for helping your lawn and trees through our cold dry winters.  Every 3-4 weeks with no significant precipitation from either rain or snow, pick a warm day and start watering early to allow the water to soak into the soil before the temperatures drop to freezing at night.


Give your lawn and trees a normal amount of water. You don’t have to overdo it.


Give south and west exposures a little different attention, especially if they slope. South and west facing lawns need water about every 2-3 weeks or if they are especially dry or hot looking. Again, don’t overdo it.


If you have any questions, give us a call at 303-232-0666 or email us at


Christmas Décor


It is that time of year again.  Christmas lights will soon be going up all over town.  If you have used our holiday lighting service in the past you can give us a call go authorize for this season.  If  you are unfamiliar with this service just give us a call and one of our representatives will meet with you and discuss some options. 


Thank You


As our busy season comes to a close, we would like to extend a sincere thank you to all of our clients.  Things around the office often become very hectic and we cannot always respond as quickly as we would like.  Please know that we value our relationship with you and enjoy helping you care for your trees, shrubs, and lawn.  Your patience and patronage is very much appreciated.