Succulents will usually have more slender, thornless stems and thicker leaves. Sandy soil mixes are recommended. Special cacti soils can be easily prepared as long as all the ingredients are free of soil-borne diseases. A good starting mixture for desert plants might include equal parts of good garden soil, coarse builders sand and peat moss. Add one-half cup of bone meal to each 12 quarts of mixture to supply phosphorus.
Planting is best in clay pots that allow the soil to dry out quickly between waterings.
Robert Nuss is a horticulturist at Penn State. He coordinates all extension horticulture programs. He has bachelor's, master's, and doctoral degrees in ornamental horticulture and has been on the Penn State faculty since 1966.