Fall Storms Wreak Havoc on Campus Trees

Once again, the Boulder Valley was visited by an autumn snow storm massively damaging trees throughout our campus.  Many of our trees were still very much in leaf causing them to catch enormous amounts of the ice and snow as it fell early in the mornings of October 26th and November 2nd.  The damage to campus trees was among the worst of the last several decades affecting, in some way, nearly every tree on campus.
This event tested our work unit in a variety of way.  It also presented us another opportunity to work with our colleagues in Housing Services, Athletics and CUPD, as well as the City of Boulder. 

Our immediate concerns and actions were aimed at identifying and mitigating the dozens of hazardous situations created by the snow loaded limbs which were failing and shedding off of trees all over the university grounds.  The storm was indiscriminate, harming trees of all species, size, age and condition.

The entire Outdoor Services team, as well as many members of other Facilities Management shops, helped by responding to emergency issues as they surfaced throughout campus.  Staff began pulling down damaged hanging limbs that they could reach and taping off areas where limbs were dangling high above sidewalks and building entries.  We reacted to the largest and most dangerous situations with our Versalift truck as soon as the terrain was passable, pulling down large limbs that were snagged up in the canopies of the higher trees.  We will be going back to all of these sites to conduct canopy inspections and make clean-up and finish cuts.  That work will take months to complete.

Once the weather had let up enough for us to access most areas with our lift truck, we divided the entire Outdoor Services team into units to begin the clean-up process.  The crew of Arborists assembled a ground support team and continued to remove high hazards.  The rest of OS created teams to buck up the larger branches on the ground, load and transport this material, and operate mobile stations to chip the wood and brush into roll-off dumpsters.  We also assisted the Housing Department Grounds staff with their clean-up and chipping.  All of this material was taken off campus and ran through tub grinders to be utilized as mulch material.  The OS crews did an outstanding and efficient job of handling the huge amount of material they faced.   We were very happy to have completed this difficult and dangerous task without any known injury to any of our staff or to the public.

A small number of trees were damaged severely enough to warrant immediate removal.   Many more were damaged to an extent that will require us to assess, over the coming months, if we can retain them and nurse them back to health or conclude to remove them.

Thanks to Ryan Heiland for the photos.

-Vince Aquino

The Good and The Bad

In recent weeks the leaves have begun to fall which poses a couple challenges, both good and bad.  Leaves alone are a great source of organic material for the soil profile so we work very hard to make sure that we capture as many of the leaves as we can and mulch them back into the turf areas on campus.  Mother Nature puts a lot of nutrients into the trees and shrubs, so to pick-up the leaves and remove them from the system is not a good management practice.  (In a later post I will describe our methods of mulching such a large amount of leaves.)  Also, if not done properly and in a timely way leaves can also be a bad thing.


Along with it being a good practice to keep the leaves as a source of nutrients for the soil, and microbial life care must be taken so that the leaves don’t sit too long without being mulched.  Recently we had one of, if not the most, damaging snow storms in CU's history related to landscape tree and shrub damage.  The reason this happened is because with such a large and early storm, the majority of the trees on campus still had their full canopies to hold onto the snow.  Being so early in the fall, the turf had not hardened off for the winter yet either.  We spent two solid weeks with our entire staff working non-stop to try and make the campus safe from falling tree branches.  Just prior to the storm the leaves were starting to fall, and the heavy snow brought down not only large amounts of trees, but also defoliated the majority of the leaves, leaving extremely thick layers of debris on the still lush turf.  Once we started to get a handle on the safety aspect of campus and began to make progress on the clean-up, I started to take a look at the turfgrass under these thick leaves.

As you can see in the above picture the turf has a yellow look to it; this is called chlorosis.  It is evident when the plant is unable to make and sustain chlorophyll due to a lack of sunlight.  Since the plant is still in a stage of growing, it is still in need of nutrients and with the thick coating of leaves, was unable to produce the amount of chlorophyll needed.  This situation, if left unchecked, will cause loss of plants.  Depending on how dense the cover it can kill off an entire area and when the spring comes around the turf is all dead in that location.  The other scenario you can be faced with in this situation is lack of oxygen and abundance of moisture which can cause turf disease, again resulting in loss of plant material.  So obviously we had to make some adjustments to our manpower and clean-up operation.  Once the campus was in a safe condition we pulled a few staff member to start the process of leaf mulching.

If you were to see this in person the turf will almost have a look of being rotten.  Like any other landscape, debris in the early stage of decomposition is very limp, very damp, and over all just not healthy.  Luckily this situation though is very treatable just by simply blowing the leaves off and allowing the affected area to get some sun and air.  The condition will not be sustained and everything will return to normal.

You can see in the above picture that the leaf blades are yellow and in some cases brown.  The blades that are more of the brown color are the plants that are further along in the process and are starting to die off.  Some of those individual plants may or may not come back around.  I believe that we caught the situation early enough and made corrections so that we will not have any noticeable damage from this event.

So again, leaves are great for your home lawns and gardens but you need to follow the classic idea that there is such a thing as "to much of a good thing."  :-)

Ryan