Many gardeners are familiar with upright varieties of sedum, such as Sedum 'Autumn Joy,' as excellent plants for late-season color in the dry hot days of late summer and early autumn. But there are also several varieties of low-growing sedum that are very good as ground covers in hot, dry areas of a landscape where turfgrass and other plants struggle to survive.
The Sedum genus of plants includes between 400 and 500 individual species, often known collectively as stonecrops, so-named because these are plants that not only tolerate dry, rocky soils but positively thrive in them. There are sedums ranging from about two inches tall up to about three feet; some species are hardy up to USDA hardiness zone 3, while others are best limited to warmer climates. There are both annual and perennial sedums, and all are fleshy succulents. Sedums store moisture in their leaves, which is the reason why they work so well in hot, arid locations.
All sedums are remarkably easy to grow and propagate. With upright varieties, a single branch or even a leaf stuck into the ground will quickly root and become a new plant. Low-growing sedums spread themselves over the ground readily, but they are not invasive and have shallow root systems that are very easy to remove from areas where you don't want them.
All sedums flower, but these plants are usually grown mostly for the foliage, which comes in interesting shades of green not found in most other plants. There is no talent required to grow sedums, and the only way they can be harmed is if they are overwatered or planted in garden soil that is too moist.
Ground Cover Sedums
Of the hundreds of sedum species available, here are some of the most popular species and cultivars for ground-cover use:
- Sedum album has white flowers and green foliage that turns reddish in autumn. It blooms in early summer.
- S. album 'Murale' is an album cultivar with bronze foliage and pink flowers. Bloom time is early summer.
- S. divergens blooms in midsummer with yellow flowers. The leaves are green but show a reddish tinge in full sun.
- S. ewersii blooms in late summer with pink flowers. Leaves are blue-gray in color.
- S. Petrosedum rupestre 'Blue Spruce' has bluish needle-like foliage resembling that of some evergreen shrubs. It works well as a transition between around low-sprawling evergreens, such as juniper or yews.
- S. Hylotelephium sieboldii has silver-blue leaves with distinctive red edges. The plant combines well against the foliage of any other plant and is especially good for brightening dark corners of a landscape.
- S. Hylotelephium telephium 'Purple Emperor' has plum-colored foliage that complements silver-colored foliage or flowers with yellow blooms.
- S. Petrosedum rupestre 'Angelina' is a gold-leaved sedum that turns bronze when the weather turns cold.
- S. Sedum tetractinum 'Coral Reef' is one of the few sedums with a warm yellowish color. It is an excellent creeping ground cover that mixes well with dark greens.
- Sedum 'Sublime' has primarily green colors that make it a good replacement for turf grass in areas where grasses and other traditional ground covers won't grow.
Growing Ground Cover Sedums
Sedums are among the easiest plants to plant and care for. They actually prefer poor, dry soils, but will thrive in almost any soil provided it is well drained. Damp, soggy soils will cause the plant to rot. They like full sun but will tolerate some shade, and they generally require no watering at all except in periods of drought. Little, if any, feeding is required.
To propagate the plants, simply dig up a small section of the plant containing both leaves and roots, and plant the section in any garden locations. Sedum is almost foolproof to grow.
Sedum is plagued by very few diseases or insect pests, but slugs and snails may sometimes attack them, and scale and mealybugs are occasionally found.
"Drop and Grow" Sedum Trays
Sedum is easy to grow in most areas, but a new product called "Drop and Grow" may make it even easier. Costa Farms of Miami, Florida, is marketing pre-vegetated tiles of live plants, including ground-cover sedum, growing in mats of coconut fiber. Costa Farms products are sold at many retailers, including Costco, Lowe's, and Home Depot, as well as at Amazon and other online retailers.
"One of my first introductions to sedum was the old variety Autumn Joy," says Costa Farms' spokesperson Justin Hancock. "While Autumn Joy has its merits, I started to discover other varieties that suited my gardening style better."
Drop and Grow combines a variety of low-growing sedums in a 10-by-20-inch tray. The sedum is living in a shallow coir base (coconut shell). The gardener lays the coir tiles on bare, loose soil, adds a thin layer of mulch, and waters well. According to Hancock, "The plants take off and create a carpet of color in three to four weeks." You can cut tiles into any shape you want. The tiles can also be used in DIY craft projects.
The newly placed sedum roots down through the coconut fiber and into the soil below. "After the plants are established, there's no need to water more than once weekly," says Hancock. "You may get by watering less than once a week. Sedum does not tolerate standing water and it is very drought tolerant.” Drop and Grow's coconut fiber biodegrades after the sedum is rooted. "Because the mats are made of organic matter, they actually improve the soil as they decompose," Hancock says.
Note that tiles should be dropped onto the bare ground where all prior vegetation has been removed. The sedum bed should be as dense as possible to help prevent weeds. Drop and Grow tiles are live and green at purchase. "We fertilize the tiles as we grow them, so they are ready to grow and expand," says Hancock. "The fertilizer should continue to nourish the plants for at least several weeks after planting. Once established, they don't seem to need fertilizer." If bare areas develop, plant new sedum in that spot.
According to Hancock, the tiles are created with different geographic regions in mind. Some are cold tolerant to zone 4, which covers most of the northern U.S. Some sedum varieties are semi-evergreen. Others may go dormant for the winter, but they’ll leaf out and resume growth the following spring. They need no special winter care.