Mycorrhizal Inoculation

A Technical Report from The Bartlett Tree Research Laboratories

The health of a tree's root system is an important factor in the well-being of the entire plant. Many actions can improve root health such as mulching, fertilizing and managing soil moisture. An important factor for improving root health is the management of mycorrhizae. Mycorrhizae are a symbiotic relation between a fungus and a root system, which exists on nearly all trees and shrubs. Mycorrhizal fungi stimulate root growth and increase the absorptive root area by sending long hyphal strands into the soil. Some mycorrhizal fungi form a protective barrier or mantle around fine roots. The mantle and hyphal strands increase water absorption during drought, enhance nutrient uptake, and provide a barrier to root disease organisms. In landscape situations, mycorrhizal inoculum is injected into the soil in a water slurry. Soil injection of these products can significantly increase root growth in low fertility soils compared to the non-treated control.