Wednesday, May 31, 2017

Post Drought Stress Symptoms

Post Drought Stress Symptoms

Although we are getting what appears to be adequate rainfall now, we are still seeing symptoms of drought stress or "post drought stress".    These symptoms may vary from wilting and slow growth to smaller than normal leaves and entire canopy death.   While some of these symptoms may have occurred last summer and into the fall there seems to be a continued showing of cracked trunks and branches with die back occurring on trees and shrubs now even though we are getting good rainfall.

Most of these problems relate back to a failure to water the plants adequately through an entire establishment period.  Trees, particularly those that are field grown and sold balled and burlapped are particularly susceptible due to the amount of root loss that they encountered when harvested.  Typically, a tree takes one year per caliper inch to get re-established so a 2 inch caliper tree will take 2 years of careful monitoring and extra care to see that the root ball doesn't dry out to reduce the potential for drought stress.  Some plants, such as Leyland Cypress and many flood plain species are drought sensitive and may require extra care to keep them from drying out.   Here are a couple of samples from a Sweetgum tree that was planted just before the drought of 2016 and is showing drought stress this spring:
   Note the cracking in the main trunk!↘







For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.