CO-Horts Blog

Monday, November 18, 2019

Drought hits most of Colorado Again, pray for snow!

By Susan Carter
Here we go again.  Many of you remember the drought of 2017-2018, second worst on record.  Some parts of our state where there is no irrigation did not even bother planting crops; some areas were on water restrictions and then came the snow the winter of 2018-2019.  That was a godsend.  If we would have had two years in a row of severe drought, we would have been hurting for water resources.  With the winter snow and the wet spring, sources of irrigation and domestic water filled up beyond what was expected.  For a brief period, the entire state had no, zero, nada drought.  Then the drought started creeping up from the southwest corner again.  Now ONLY the north to northeast corner of Colorado is not in drought.  Note the Water year starts in October.
So what does this mean for your garden and perennial plants including trees?  Drought stress is not something that just goes away because you watered once or because for a brief period, the state was not in drought.  Water is one of the key ingredients in photosynthesis and other plant processes that help the plant create carbohydrates and move water and nutrients throughout the plant.  When plants cannot adequately produce food, they use up their reserves.  Each plant, like people, is different due to the environment and the type of tree as well as its specific genetic makeup.  So some plants will bounce right back, where others will stumble along for a few years before they give up because they have exhausted their resources.  In addition, stressed trees attract insects that can also exhausts the tree’s resources as they cannot fight off the insects or recover from the damage done.
Old Pinon Pine with IPS Beetles- Incorrect water stress
Photo By Tom Ziola
Leaf Scorch- drought can be a cause
Photo by Susan Carter

So how do we deal with drought that seems to come more often?  Well we can properly water, winter water, direct downspouts etc… to keep what we have alive.  Then we can start by replacing plants that have died with more drought resistant plants.  Remember, if you have a tree in a lawn and you remove the lawn and install rock what have you just done?  The root system of that tree is totally under the lawn.  A tree’s root system is at least twice its width or 2-5 times the height.  Ninety percent of the roots are in the top 12-18" of soil.  That area needs water.
Watering photo from CSFS
Trees are like people in that they do NOT like change.  To change a watering zone from frequent watering of turf to watering the tree root zone, you have decrease the frequency slowly.  You have to wean it off the watering to the appropriate 10, 20 or 30 day of watering interval for the type of tree and environment. (Watering Mature Trees)  I could go on with more ways to save water, but I think that is a blog for another day, the point is think about drought affects, where you water and why you water and come up with a long term plan. 

Snow around Plum trees
Photo by Susan Carter

In addition, we can hope for more snow!  If the ground is dry and frozen when the snow arrives, it does not hydrate the parched soil.  If the soil is dry, but not frozen water so there is moisture in the soil (but not saturated) so if it thaws again there is water available to the roots.  Plants need to go into the winter with moisture available to them as they continue to respire and give off moisture even if they have dropped their leaves.  Of course evergreen plants like pine and spruce trees, evaporate due to having leaves all winter.  A dusting of snow is not very helpful either.  It can just evaporate.  Snow at least 6” deep can insulate the ground and provide enough moisture when it melts to help.  Then there are the reservoirs that need to fill so we have irrigation and domestic water.  So let it SNOW!

Susan Carter is the CSU Extension Horticulture and Natural Resource Agent for the Tri River Area.


  1. Thanks Susan! Good reminder for us. We are transitioning back yard from lawn into pollinator friendly perennial low water plants. There are several mature trees in back yard too though. We probably unintentionally neglected their water needs this year thinking they would no longer miss the previous lawn-watering scheme