Growing to New Heights

An Ash tree that was reduced in height by 40% to provide a vista of the mountains. This tree requires annual pruning to maintain the height.


Here it is the middle of July and the grass is still green. Thunderstorms have been rolling through and the branches of healthy trees are full of leaves. Things are likely to change as we move into August, with continued heat and sun. Often trees will start to shed their excess “solar cells” or leaves that don’t produce enough energy and consume too much water. In the arborist world we call this “compensatory leaf drop” and it is very common to see at the end of summer as trees adjust to make the best use of their resources.

For now, our trees are growing and many of them are reaching new heights. It’s the height of trees that can often cause frustration. Along the front range many people have purchased their homes and installed their landscapes, with the intent of enjoying the beautiful snow speckled peaks to the west. What happens when that cute little eight foot tall blue spruce planted 25 years becomes a 60-foot mature tree and blocks the once clear view of the Rockies?

These conversations are taking place throughout our community, and there is the potential for conflict and disagreement among neighbors. There is also the opportunity to come together and find common ground. Some may say it’s a great opportunity for practicing “empathy” and the golden rule of treating others how you would want to be treated.

The arborists role in these tricky situations is to bring a level of expertise and knowledge of trees that can inform these decisions. We can present tools, solutions and options for meeting different objectives. 

Each tree species typically has a final growth height. For a cottonwood that can be as high as 100 feet (30.48 m). For a blue spruce in the suburban landscape this is usually around 75 feet (22.86 m). 

When the height of a tree is reduced, whether it is by an arborist or a heavy wind breaking branches, the tree experiences a hormone signal that tells it to grow. It will adjust its resources to grow as rapidly as possible back to the original height. For a cottonwood this might be as much as 2-3 feet (-0.91 meters) per year.

There are some tricks of the trade and tools available to help us slow or control this growth response. One of those tools is a growth regulator that simulates a hormone signal in the tree. Many utility companies have used this material to manage trees under power lines.

Before you ask someone to cut your tree in half or contemplate sneaking into your neighbor’s yard at night to cut off that one offensive limb, try speaking with an educated and experienced arborist. Once you cut it off you can’t put it back!

Josh Morin is an ISA Board Certified Master Arborist and co-owner of Taddiken Tree Company, a locally owned and operated company.