You've got a green thumb, and it certainly shows. Your home is filled with plants of all types, and your yard is lush with vegetation. You've devoted many hours to creating a beautiful lawn and garden and have tackled almost every part of your landscape, except for that small hillside near the creek. You planted grass there, and you mow it regularly, but that's as far as you have gotten.
As with any garden, selecting the right plants for the environment is important. There is a risk of erosion with a hillside, so you will want to make certain that you select some plants that will help keep the soil intact. Deep-rooted plants will work well for that as will some groundcovers.
As you are selecting plants, take their light and water requirements into consideration. If the hillside is shaded and wet, then you will want to select plants that can grow in low-light, moist conditions. If it is sunny and dry, then you will want to select plants that can grow in sunny, dry conditions.
Once you have zeroed in on some plants for your hillside garden, you will need to devise a plan for their placement. Since you are dealing with a hillside and want to prevent erosion, you may want to try terracing. Using stone blocks or some other material, you can create a series of terraces in the hillside. The plants will sit flat on the terraces, allowing you to water them easily and more efficiently. If you have trees in your hillside garden, you may want to create a moat around the bases to prevent water runoff.
Depending upon the severity of the slope, you may need to take additional measures to prevent erosion. You may want to build a retaining wall or add some boulders or rocks, both of which will retain the soil. To complete your garden, you may want to add a few decorative touches, like a bench or a statue.
Gardens can be created on hillsides. It just takes a little time and thought. Put in the effort, and you're sure to be pleased with the results.