Covering the roots with soil may harm them. Some trees are more
sensitive to added soil than others. Oaks are particularly
sensitive to changes in soil level. If the roots die, the rest
of the tree will soon follow. You might consider converting the
area to a garden filled with shade-loving ground covers. That
way your children will avoid the area altogether. To plant
shallow-rooted ground covers around the roots of a tree, cover
the roots with no more than 1 inch of loose soil so that water
and air can penetrate. Buy plugs of the types of plants you want
to install (look for ones that thrive in dry shade); plugs are
smaller and will disturb the surface roots less than larger
container-grown plants would. Carefully dig around and between
the roots, and find or make small planting pockets where you can
work in some compost and peat moss. After the plugs are in,
water well and keep watering so the ground constantly stays a
little moist, which helps the newcomers get established. Once
they are, they will start t