Temperature swings took a toll on trees Email
Written by ALCC   
Tuesday, November 12, 2019 03:00 AM

Evergreen with brown needlesIn October, Colorado’s Front Range experienced extreme temperature changes. Some immediate effects are being seen, but we won’t know until spring just what the long-term effects may be.  

In many places, trees were not ready for warm days that quickly led into freezing nights. Colorado Springs saw one of its biggest 24-hour temperature changes in history, going from 80 degrees to 19 degrees. The most visible effects have been seen on young trees, particularly evergreens, that were planted within the last two to three years. Those evergreens, particularly some pines, have shown browning on needles—in some cases turning completely brown.  

The freeze damage looks very similar to drought damage,” explained Levi Heidrich, Heidrich’s Colorado Tree Farm Nursery. “ 

There are some similarities to the November deep freeze in 2014, which followed a very warm fall and had devastating effects on stone fruit trees and shrubs. After that weather event, some plants were able to bounce back from damage the following spring while others were a loss. Some trees that turned entirely brown were still able to push out all new needles in the spring.  

Established trees that just have browning at the tips of leaves may still have buds that are viable, and they will leaf out in spring. In the same way, evergreens with brown needles may still have healthy buds that contain spring growth.  

Key messages for consumers will be: 1. Have patience. Don’t give up on your plants yet, and wait for spring to determine the extent of the damage, and 2. Extreme weather, not plant health or poor installation, is to blame. 

Experts point out that the damage is not likely due to the quality of the plants or how they were planted or maintained. Extreme temperature changes and early freezes are unexpected events that can affect young plants and trees when they are most vulnerable. 

Read more in this issue of Colorado Green NOW:
Snow management safety tips
DOL proposed rule clarifies overtime calculation for some workers
VIDEO: Using graywater for irrigation
Landscape Industry Certification by the numbers [INFOGRAPHIC]