How deep do I need to dig to plant a tree? I've got a lot of trees to plant.
Probably not as deep as you think. Digging a "$10 hole for a $2 plant" refers to the width of the hole, not the depth. Most tree roots are in the top 18 inches of soil, so the wider you work up the soil, the easier the roots will be able to penetrate it.
Plants should be placed at the same depth as they were in their container. The problem with digging a deeper hole is that the soil can settle, and suddenly the plant is too deep. That condition can slowly smother it.
Ellen Nibali, horticulture consultant, works at Maryland Cooperative Extension's Home and Garden Information Center, and David Clement is the regional specialist. The center offers Maryland residents free gardening information. Call the center's "hot line" at 800-342-2507 (8 a.m.-1 p.m. Monday-Friday) or e-mail plant and pest questions through the Send a Question feature at hgic.umd.edu.