Planting trees or shrubs on a steep hillside

Planting a tree directly into the side of a steep hill places too much soil over the roots on higher side of the hill. The soil on the high side of the hill can restrict root expansion and moisture contact with the roots. It is best to create a flat surface on the hillside to plant the tree or shrub for optimal root growth.

There are two different approaches to create a flat planting surface. Shown above, on the left, a flat step is created in the hillside. The second option, as shown on the right, brings in soil to create a raise planting area with a flat surface. A combination of both techniques is an option too, where a lesser amount of soil is removed from the hill and that soil is then tossed below the planting area to create a shelf or step in the hill. With this combination method, remember to work the soil in the planting area down as deep as the root ball is tall, and also work the soil in a circle one to two times the width of the root ball.