We have an enormous sloped rock garden in our back yard, supported by a retaining wall. There are several hundred very large rocks surrounded by various ground cover and perennial plants. My goal is to have the empty dirt spaces totally fill up with plants. However, the soil is too sandy and is being washed down with rain and snow run off. Can I put compost on top of the existing soil and plants, or would you suggest trying to mix the compost with the existing exposed soil? Also, I have reoccuring weed that I can't seem to kill. It looks like a three leaf clover and spreads like ivy. Several branches grow out of the dirt together and it is impossible to pull the roots out. I have been spraying them with Round Up, but they come back every year. Any suggestions? Thanks so much for your input! Stacy,
If you are having problems with runoff I would not suggest you put any compost in the soil, instead try putting potted plants in the open areas. Amending the soil with compost is a good idea but with the soil running off I feel that it would not be worth the time and money to amend the soil. The positive side to potted plants is that you can pick out decorative pots to plant in and do not have to worry about runoff leaching the soil from around the plant and possibly killing it off. As for the weeds you can try the Garden-Ville Natural Weed Control and apply it directly to the plant trying to avoid over spray. Your other choice is a product called Image, it is a broad leaf specific herbicide that you can pick up at any lawn and garden center. | 
