As succulents, sedums do not usually require regular watering. Their leaves and stems store moisture, so they are able to cope between rains. In fact they like their soil to dry out between waterings. Water them only when they are first planted, and just before the ground freezes hard for winter. In periods of severe drought water them every week or ten days, allowing the water to soak deeply into the soil. Because it is likely to be sandy soil, water will soak in rapidly, so water for only 10 or 15 minutes each time.
Sedums can manage in poor soil, but they appreciate fertile soil too. Sprinkle a handful of an all-purpose granular fertilizer on the soil around sedums each spring for the rain to soak in. If the sedums are already in soil that is fairly rich, fertilize every other year. Do not overfeed these plants.
Spread a layer of an attractive organic material on the soil around the base of showy sedums where they are situated in the perennial border or elsewhere. Two inches or so of wood chips, shredded bark, or similar cover will discourage both weeds and the evaporation of water from the soil. Do not allow the mulch to touch the stems or foliage, since the moist material may promote rot. A layer of small stones makes a good mulch also and avoids this problem.
For more information see file on Using Mulch.
Sedums usually do not need pruning or clipping. One exception is in the case of showy sedums. When wet, their fully developed flower heads sometimes become too heavy for their 18 inch stems. If this is a problem, next season trim the stems by about 1/3rd early in the summer before the flowers form, so that they will be shorter and sturdier by fall. Some other types of sedum benefit from cutting back early in the season, becoming bushier and more compact.