How important is my soil to the health of my tree?
Soils are more than just dirt – they are alive. Healthily soils contain thousands of living organisms from microscopic bacteria and fungi to insects and earthworms.
These soil flora and fauna provide multiple benefits to trees and shrubs, including freeing essential elements from organic matter. Worms and other arthropods are particularly important because they create macro pores that plant roots can inhabit and water can move through.
Plants live in soil and healthy soils are the key to healthy trees. If your trees are looking “sickly” or are showing signs of a nutrient deficiency, it is prudent to take a soil sample for analysis before beginning a fertilization program.
Trees require 15 essential mineral elements for proper growth. If just one of these nutrients is out of proportion, too little or too much, plant health and vigor will suffer. Deficiency or overabundance of these elements can mimic one another as undesirable leaf color or tip growth, thus making a soil sample crucial to proper fertilizer application.
Another piece of information a soil analysis will offer is soil pH, which is a measure of soil acidity or alkalinity. Most plants prefer a pH between 5.5 and 7. The pH of soil plays an important role in element availability.
When soil pH is either too high or too low, certain elements become tied up in the soil, making them unavailable for plants to use for their metabolic processes. In these cases, applying a traditional fertilizer will not solve nutrient deficiency symptoms in the tree. The soil will need to be amended to alter the pH so mineral elements will become available for plant uptake.
Plant nutrition and soil chemistry can be more complex than simply throwing down some fertilizer. If you think your tree is suffering from nutrient deficiencies, it is prudent to have a qualified arborist help diagnose the problem and develop a soil management plan.