Question
Help! My backyard is at the top of a city hill & is eroding into my neighbors yards. It is a very shady yard with 4 big Maple trees & a huge pine. We are also having a recurring problem in that grass seems to have worn off in great patches & the ground is hard as rock with many small tree roots uncovered. What can I do to salvage it?

Answer
Hi Ellen, Planting more trees,shrubs and groundcovers are your best solution.  Which ones and where may be better answered by a local landscape designer.  Grass (pasture) and trees (forest) have nothing in common.  It's difficult to grow full sun loving grass in the shade of the trees, not to mention the competition for water and root space.
You may even need to add some retaining walls if the hill is unstable.
Groundcovers like Vinca minor or English ivy will cover a shady hill very quickly and if you spray feed them often, they're not too picky about soil type.
If you must have grass, consult your local nurseryman about the best type and care.  You may want to consider terracing the hill to make it more useful.  Jim