 Re: Air-spade
Vertical mulching at our company usually involves backfilling the holes with compost. It keeps the holes open enough to allow for air and water to penetrate while gently "feeding" the soil.
We used to use a drill with a 2" auger bit, but with the air spade, it's faster and easier. Holes are usually spaced from 12 to 18 inches in a grid starting about 1 foot from the tree and continuing out to several feet beyond the drip line.
We've also tried Dr. Watson's method of radial trenching - trenches 10 to 12 inches wide, 8 to 10 inches deep radiating out from the trunk at 45º angles.
One client even let us air spade her entire front lawn. We turned over about 2 thousand square feet of soil down to a depth of 12 inches and added about 20 yards of compost to the root zone of a large American elm. While it didn't give me the miracle results I was hoping for, the tree is significantly improved and the client is happy. |