Replacing Soil in the Root Zone of Mature Trees for Better Growth

"Soils were replaced in various patterns within the root zone of mature landscape trees as an alternative to surface mulching. Care was taken to minimize the damage to the root systems, through careful positioning of the excavations, or use of hydraulic excavation procedures. Tree roots grew better in the new soil mixes than in the original site soil, exhibiting up to a 320% increase in fine root density and up to a 68% increase in rooting depth. Declining annual growth rate trends were reversed by the treatment in Tilia and Platanus. Soil replacement has potential as another useful tool for treating declining trees." [Abstract]