Sonoma County Master Gardeners Helping Sonoma Gardeners

By Sara Malone, Master Gardener

As most perennials are slowing down for fall, Sedum 'Autumn Joy' lives up to its name and bursts into bloom. Alternately referred to as S. Autumn Joy or S. 'Herbstfreude' (which is German for Autumn Joy!), this upright member of the Crassula family is a natural for Sonoma County gardens. It is drought-tolerant, not fussy about soil as long as it is well-drained, and puts on a show at the time of the year when our gardens can use a burst of color. Its large rosy-coral flower heads stand about 15" -18" high on a plant about 2' wide at maturity. It combines equally well with other flowering perennials such as Agastache or Salvia, or with ornamental grasses. I have some in a bed with Verbena rigida - the soft coral of the Sedum is a lovely contrast with the electric purple of the Verbena, and I have another group at the edge of an ornamental grass garden, sharing the space with Calamagrostis, Pennisetum and Miscanthus, all of which are in bloom now, too.

Autumn Joy starts its growth in the spring with small, Brussels-sprout-like buds at the soil level. These gradually grow into attractive fleshy stalks and leaves. The flower buds form in early to mid summer, and the plant blooms for 6 weeks or so beginning at the end of August/beginning of September. The flowers start out pale and gradually darken in hue, ending up pinky bronze. I leave the stalks on the plants until spring - all winter long the birds sit on the large spent flowers and pull seeds out, and the deep mahogany seed heads give the garden winter interest. In late winter or early spring, either cut or break the stalks off at ground level - where you will already see the buds forming - and the cycle repeats itself. When the plants get large they can easily be dug up and divided to make more plants.

Despite all of the foregoing attributes, my favorite thing about Sedum Autumn Joy is that the bees adore it. When in bloom the bees cover the flowers, energetically collecting nectar for their winter stores. This is the time of the year when nectar is very scarce in the County - the natives are not producing nectar and most of the cultivated crops are not, either. So the bees really appreciate some Autumn Joy to get them through the winter. Between the bees in the fall and the birds in the winter, this is one of the best habitat plants in my garden.

Autumn Joy is easy to care for - it just needs full sun and not too much water. If grown in soil that is too rich or if given too much water it will flop over when the flower heads get heavy. This can be avoided by reducing the water, staking the stalks, or cutting the plant back by ½ in May or June. Insects and diseases are generally not a problem, although sometimes they will get an infestation of black aphids (especially if they are not in enough sun) - good, strong shots of water from the hose nozzle should take care of them.

Sedum 'Autumn Joy' is available at most nurseries in the County - try Mostly Natives in Tomales or Cottage Gardens in Petaluma or Sonoma Mission Gardens in Sonoma. I saw it not long ago at Home Depot's Nursery and Garden Center in Rohnert Park.