Horticulture Q and A from the Mojave Desert
Vertical mulching is a soil management technique that is actually quite old. It involved auguring or drilling some holes in the soil to open the soil for better drainage of water and admitting air around plant roots. It was done when the soils were to compacted and plants showed signs of stress and dying. Holes were created deep enough so that water could drain and air could reach the roots. Around trees and shrubs this could be 18 to 24 inches deep. In turfgrass gasoline driven aerators were used to punch holes in the soil about 4 inches deep. In times past, post hole diggers were used. This gasoline driven, hydraulic auger is being used for vertical mulching. When soils are compacted, they don't drain quickly and plants appear to be suffering, vertical mulching may make a huge difference.