Tree Talk: The big, beloved sedums

Come October, garden columns are usually filled with stories about pumpkins, chrysanthemums or trees ablaze with autumn color. Rightly so, but there is another plant that heralds the season in equal splendor: sedums.

With nearly 300 species in the genus, most are known as stonecrops, low-sprawling plants with plump, succulent waxy leaves in shades of green, gray-green, celadon, pink and burgundy. Most sport clusters of tiny, vibrantly colored flowers. You see them in rock gardens and atop tile roofs in Europe, or happily crowded into low terra cotta pots gracing table tops and stone walls in full sun.

Little known, or at least little known until the last two decades, are the tall-growing sedums. These are prized perennials to grow in the garden or in containers. Two species forged the trail: Sedum spectabile, imported from China and Korea (growing to a height of 18 inches), and S. telephium, a native from Eastern Europe to Japan (a 2-foot clump-forming plant, as wide as it is tall). These were the only big sedums being grown. Then came a hybrid of the two, S. “Autumn Joy,” with its bold domes of blossom emerging pink and then aging to bright copper and darkening with age.

What made these plants special was their unusual foliage, their beautiful flowers that appear in late summer and early autumn. Their drought tolerance and ease of maintenance was a huge plus, as was their adaptability to in-ground or container gardening. Paired with ornamental grasses, their unusual foliage was a show stopper.

Suddenly these statuesque sedums caught on, and propagators and hybridizers have now introduced a number of new and very interesting plants. S. “Autumn Joy” was followed by S. “Autumn Fire,” known for its rich fall color. Then came S. “Neon,” with electric pink flowers atop green stems and leaves; S. “Stardust” is a similar plant but with very large white flowers. The blooms of S. “Carmen” are nearly red.

The introductions continued. Boutique nurseries were offering S. “Cloud Walker,” with maroon stems and leaf tips and large pink flowers. The dark red stems, gray-green leaves and pink flowers of S. “Matrona” had competitive gardeners sleuthing and keeping their sources top secret. Variegated leaves of jade green with creamy white edges and pink flowers had gardeners chasing down S. “Variegatum.”
It all got a little annoying, but the genus Sedum would have none of it. An egalitarian plant, if ever there was one, sedums are a cinch to propagate. Almost any stem clipped, top and bottom, with five or six leaves left in place will root in soil. Dusting the cut ends with some rooting hormone powder is added insurance but really not necessary. This month, take a cut stem of one of these sedums, scoop out a shallow trench in a pot of soil or in the ground, lay the stem flat in the trench, cover it with half an inch of soil, leaving some of the leaves sticking out. Next spring you’ll have little plants sprouting all along that stem. I’ve increased my collection to dozens of sedums this way. They prefer loose, rich soil and do well with a modicum of water. Once established, I feed mine with a liquid plant food monthly, from April through September.

Sedums also transplant and divide easily. Once, on a hike around the suburbs of Vancouver, B.C., with the artist Zoran Malinovski, I shocked him as I shouted out with glee and jumped into a thicket having spotted a Sedum “Autumn Joy” that had been dumped and subsequently rooted. I insisted that my startled friend return with me to the spot with a shovel. We dug the plant up, carted it back to his house and planted it in a pot, to the delight of his wife, Angie. Now it fills a cherished spot on their patio, a leafy sculpture in spring followed by a floral show in summer and autumn, always abuzz with honey bees that fly off to pollinate the rest of their garden. No doubt this noble plant will make its way onto one of the painter’s canvases.

Back in the day, I scouted a garden owned by a renowned plantswoman. At that point, these robust plants were little known. She had massive sweeps of sedums. In full sun, they were thriving in exuberant bloom along a blisteringly reflective driveway. I remarked on the spectacle.

“Oh yes!” she said. “Once I sedum, I knew I had to grow 'em.” Then she threw back her head and let fly with a rumbling laugh. I rolled my eyes at that groaner and then discharged a mild, albeit genuine chortle.

Yet, the point was made. Few gardeners who get exposed to these big succulents are able to resist them. They’re beautiful, low maintenance, drought tolerant, long lasting, easy to propagate and, in leaf and blossom, a perennial in a class unto itself. Add to that, they have the power to make even the corniest joke resonate with any gardener who’s ever encountered them. In short, you just gotta sedum to believe 'em.