Tuesday, November 15, 2016

Protecting Trees and Shrubs from Extreme Temperature Drop by Carol King

Image wallpaperscraft.com
Our first round of really cold weather is headed this way.  Although it is in the 70’s today and tomorrow, Thursday and Friday night are predicted to be in the teens and twenties.  What comes to mind is September 2014 when we experienced a dramatic drop in temperature that destroyed many trees and shrubs. Could this weather event be a repeat of that one?

I spoke with Patti O’Neal, CSU Jefferson County Extension and she gave me this advice:
  1. We have been watching, and trees have begun their dormancy process now, whereas in 2014, they had not. 
  2. The temperature won’t drop like it did overnight in 2014.  This will happen more gradually over a two day period so the element of “sudden-ness” will not hit the way it did previously. 
  3. The way things have been predicted lately and the difference between 2014 and what has actually happened have been pretty disparate. Some areas of the metroplex have hit 32 degrees, while Arvada, for instance,  has not been below 39 yet. 
So what to do?
In the event the meteorologists are actually correct this time, make sure you water well; trees in particular if you have not already done so this past week.  Roots go into a freeze much sturdier moist than dry and whatever the plant can take up tonight and tomorrow is just that much better.

Use a hose and sprinkler if your system has been turned off already and make sure you place the sprinkler to the best advantage of the feeder roots of the tree (at the drip line) and not the trunk of the tree.  Then make sure to unhook the hose from the bib after you finish to prevent freezing and damage to your pipes.

It is also predicted that temperatures will go back up again next week.  Stay vigilant and water during the warmest part of the day into next week if you can as the ground will not have frozen yet. 
The fact that the trees have begun their dormancy process should protect them as well.  That was an issue in 2014 when they had not.  Where we expect we might see some further damage is on trees that were damaged in 2014 and are still struggling to recover.  Ornamental pears with bark damage from the 2014 freeze that are still trying to put on new bark, for example, might be candidates for issues.  Wrapping with paper will not help at this point.  Additional protection such as insulation, a campers freeze blanket or a hot water blanket would be a far better choice. 

In summary, the event should not be as brusque as the 2014 event on the whole, but weather is unpredictable and we should prepare as best we can at this point.