To grow healthy sedums, choose a sedum variety appropriate for your hardiness zone, and don't over water or over fertilize the plants. Sedums tolerate most soils, except for clay, as long as the soil is well-drained. Plant sedum seeds or cuttings in full sun in early spring. When sedums are established, they need little attention. Sedums propagate quickly but they are not invasive. Divide adult plants to control their growth.
Depending on the sedum variety, position the plants between 6 inches to 2 feet apart. Loosen the soil 12 to 15 inches deep with a garden fork. Apply a 2 to 4 inch layer of compost and mix it into the soil. To plant sedums from seed or cuttings from small varieties, simply place them on the soil and apply a thin layer of soil over them. To plant large sedum varieties, push a cutting into the soil. Sedum seeds and cuttings grow roots and become established quickly.
Control sedum propagation by dividing the plants in the spring or fall. Select a segment of an adult sedum with a thick stem, and dig out a portion that's big enough to come out with good roots. Fill the hole with soil so the plant can grow back. Dig a hole elsewhere and replant the division, making sure the roots are level with the surface.
To reshape large sedums, cut the stems after the plant flowers. Control weeds by applying a layer of mulch to established sedums. Water sedums only when it's hot and dry, and allow them to dry out between waterings.