A few retaining walls in stair step fashion is good and more user-friendly when done but will probably be expensive. I used an erosion control blanket over grass seed with a fairly good result on one steep slope. Most grasses like sun. Many flowers like sun. Some plants that reliably reseed could help with replenishing the area and cutting down on the amount of weeding you have to do. You might also want to try the natives forum for plant suggestions that are good for your area.

Greenthumbnewbie,

My wife and I spent a year pondering the same question. When we purchased our present house, the back hill was very steep with a gravel, stone and railroad tie step system going down to the barn. Almost impossible to mow and the weeds grew wild. The property was used for horses for 9 years so nothing was ever done.

We decided to call in our landscape contractor for a variety of ideas. The long and short of it was we had terracing done using Unilock stone with caps. Right now the "old hill side" has been mulched. We will be planting this fall. We also has steps done into the old hill side to have a clear and safe way down to the barn area.

eal51 in western CT

It's so exciting to see this forum as I have barren slopes all over around the home we're building. Greennewbee, I'm having trouble visualizing your situation, but one line grabbed me--the one about having to bring in new soil. You don't have to if you don't want. Our hill has awful decomposed rock for soil, and we're building what we have by bringing in truckloads of organic matter courtesy of the county (i.e., they grind, we go pick up). It's totally free, and if your county doesn't offer it, one of the ones surrounding you almost certainly does. Some load it for you too. In any case, while it's breaking down it does a wonderful job of holding the soil and smothering weeds, and after a year or two becomes wonderful stuff that can be tilled right in. AND, although it takes years to build really nice living soil, I've planted in areas tilled with only slightly composted matter, along with bags of lime, 10-10-10, et cetera, and the plants don't seem to know their new home is still under construction.