Sedums: Showy but not temperamental

‘Purple Emperor’ sedum has vivld foliage. — peganum/Creative Commons

When you think of late-season flowers, you probably think first of chrysanthemums and asters, the dynamic duo of autumn. But let’s face it: As garden subjects, neither is without issues.

Chances are you’re buying potted mums every fall, since many grown for mass markets today are not reliably winter hardy. Even if you have mums of the sturdier perennial kind, they won’t be at their best unless you pinch them back several times early in the season and divide them regularly to keep them vigorous.

Asters? Lovely. But lacking a rabbit-free zone, you may not be able to grow them at all, since they are high on the bunny snack list. And a fungus disease known as aster wilt can strike without warning, reducing your plants to blackened sticks.

If what you really want is fall color without fuss, consider late-blooming sedums, the unsung stars of the autumn border. These plants put on a show but they’re no prima donnas, requiring very little input from the gardener.

The sedums are a large plant family, including some 300 species distributed throughout the northern hemisphere. The ones you want for fall display belong to a subgroup known as Sedum spectabile, literally “showy stonecrop,” and that’s how you’ll see them listed in most catalogs.

Showy sedums, like most late-bloomers, keep their good looks through spring and summer. True three-season plants, they produce fresh, succulent leaves in early spring and are rarely bothered by insects, disease or slugs. The immature flower heads that form by midsummer are attractive on their own merits, offering abundant, pale green, dome-shaped clusters that play well with other specimens in the flower border.

These flower trusses gradually ripen into deep rose, pink, russet or white by late summer or early fall, holding their color for several weeks before fading to brown. Even spent, the flower heads can be left uncut for winter interest and are especially pretty with a dusting of snow.

The one thing sedums do require is well-drained soil, so don’t put them in a soggy location. Give them average or even poor soil, hold the fertilizer and don’t baby them. I have them growing in raised beds around a paved driveway remote from a convenient water supply. They seldom get watered but never seem to mind.

Even before flower heads color up, sedums shine. — Ali Eminov/CC

Sedums are attractive to bees and butterflies, but not on the preferred list for most four-legged garden raiders. Bunnies and woodchucks generally leave them alone and even deer, happy to eat everything else, usually pass them by..

Plant breeders haven’t gone as wild with showy sedums as they have with certain other perennial favorites but there are still lots of choices. Perhaps the best known is ‘Autumn Joy,’ with blue-green foliage and flowers that develop from deep rose to mellow russet. Its modern successor is ‘Autumn Fire,’ which tends to grow more compactly, resists flopping over and flowers in a more vivid color. Another relation is ‘Autumn Charm,’ with leaves outlined in white; much the same look is available in the older favorite, ‘Frosty Morn.’

Some cultivars have outstanding flower color. Deep reds are featured in ‘Vera Jameson’ and ‘Ruby Glow,’ vibrant pinks in ‘Brilliant’ and ‘Neon.’ The newest sedums have dark stems or tinted foliage. ‘Matrona’ flowers in a warm, blush-pink contrasting with reddish stems. ‘Purple Emperor’ and ‘Lynda Windsor’ have striking purple foliage and the leaves of ‘Black Jack’ are darker still — very nearly black.

Sedums don’t belong with water-thirsty plants, since overly generous irrigation doesn’t suit them and can lead to stem and root rot. They are beautiful planted in masses along paths, atop walls or near entrances where their good habits will never embarrass you. They combine beautifully with smaller ornamental grasses, which are developing their feathery plumes about the time the sedums are coming into their own.

Try sedums with other drought-tolerant species such as Russian sage or with hybrid goldenrods like ‘Fireworks.’ Sedums also look terrific with lamb’s ears, a mat-forming plant with fuzzy gray leaves, and with amsonia or blue- star, a plant with fine, needlelike foliage that turns golden yellow in fall.

Fall or spring are both good times to plant the showy sedums, but early spring is the best time to divide any clumps that may have gotten too big. These plants increase at a pace that won’t take over your garden, but will give you material to move around the garden in a few years.

If you want more, propagating sedums from stem cuttings is child’s play. No special soil mixes or expensive rooting hormones are required. Just cut a stem tip in summer before flowers have formed, stick it in a container of ordinary potting soil and keep it moist. When the stem starts to put on some length, pinch back the top to encourage branching.

Indulge those temperamental delphiniums, those disease-prone roses and those water-needy impatiens if you will, but save room for sedum. There’s a lot to be said for a beautiful plant that won’t make you crazy.