How To Save Your Favorite Tree - Don't Just Look At The Pest, Look At The Past

The majority of tree health problems are caused by something other than pathogens, insects or mites. Most are caused by environmental conditions like soil compaction, mechanical injures, drought, temperature extremes and water fluctuations. Poor plant health is usually due to more than one factor and more often than not a disease or infestation is most likely a secondary agent stressing your tree. Primary agents (environmental or cultural) first stress the tree making it more susceptible to secondary agents like insects or disease.

The area around a tree and what has taken place there in the past is often overlooked for the more obvious symptoms. Concentrating on those symptoms and not on the reason for their being there will not solve the problem. Here are some things to consider.


Site conditions

Have there been any recent (as in the last few years) changes to the ground around the tree? The root zone of some species can extend out one and a half times the size of the crown, if soil compaction or construction of some sort has taken place in this area it might cause the tree to have problems with water absorption or a mineral deficiency. Too much water can be a problem too, denying oxygen to the trees roots. A soil analysis may be needed to check the soil PH and check for mineral toxicities.

Extreme temperatures either high or low.

Species type and the time of year have a large effect on the damage caused by temperature extremes. Chilling or freezing injury affects the integrity of cell membranes, trunks and steams can develop frost cracks when the temperature drops rapidly. Sunscald and high temperatures, due to the removal of shade, can have a negative impact on thin-barked trees and previously injured trees.

Chemical Injury

Any number of chemicals can kill or injure a tree but herbicide is most often the offender. Herbicides are formulated to kill plants (not just weeds), they are systemic which means they move throughout the plant. Often the foliage of exposed trees will curl and new shoot tips will be twisted. Trees can recover from this type of damage if the exposure is not too severe, but always remember to use extreme caution when using any chemical near trees.

Competition

Other trees (usually older ones) and plants can be causing your tree to decline. Competition for sunlight is the most common problem especially among Shade-intolerant trees. Growing under a canopy of larger trees may cause death of lower branches and stunted growth. Trees also compete for nutrients and water with your lawn and other plants. Remember that most of a trees absorbing roots are found in the upper 12 inches of soil..

Getting to the bottom of what is stressing your tree and causing it to decline is the first step in diagnosing the problem and coming up with a prescription for a cure. If you want your favorite tree to flourish into what you had in your minds-eye when you planted it, always keep in mind the trees environment. Caring for a tree means not only providing food and water but also caring for the environment in which it grows. You may be killing your tree without even knowing it.