Sedum sarmentosum - Spreads rapidly, almost invasive. Good for extremely poor soils. Idea for planting along ditch. Stringy stonecrop, Sedum sarmentosum, is probably the fastest-growing sedum around -- at least in the cold-hardy species.
Plant en Masse--Here, drifts of astilbe seem to tower out of a groundcover of golden sedum. Test Garden Tip: Planting en masse doesn't necessarily mean growing only a single variety. Here, several selections of astilbe combine for even more interest.