Photo Credit: Laurence Costello, retired, Univ. of CA, Division of Agriculture and Natural Resources
With so much emphasis on pest identification and control in parks, it’s easy to forget that the majority of disorders impacting landscape trees result from abiotic (non-living) disorders. However, there are several techniques that greatly reduce the chances of damage from abiotic disorders:
Selecting healthy plants that are well suited to the climate and microclimate Incorporating recommended planting techniques Providing a soil environment that optimizes a healthy root system Implementing sound cultural-management practices (irrigation, fertilization, pruning, aeration, etc.).
Keeping notes regarding the overall maintenance of a park or field, including planting and care practices that were used, can be very useful when trying to determine why a tree is not thriving. These field notes will help identify what changes in the plant-maintenance regime (e.g., irrigation, fertilizer, pruning), climate (temperature change, high winds, etc.), or construction activities may have compromised the health of the tree. Also, if a tree was planted too deeply, deep roots may remain dry while surface roots are subjected to crown rot. In other cases, weed cords or mowers damage the lower trunks of trees and provide an entryway for fungus.