Family: Crassulaceae (Orpine family)
Genus: Sedum

Picture courtesy of Oregon State University Landscape Plant Database

Now you sedum, now you don’t.

SedumI’ve been waiting for months to use that line, so I’m taking the liberty of foisting it off on you, my fellow Master Gardeners. It’s now definitely a “do” time for sedums, as we all search about for unthirsty plants while many of our traditional Whatcom County favorites suffer in this atypically hot and very dry summer. Most of us are tired of hose duty by mid-August, and all of us are concerned about appropriate use of water in our landscapes. Recommending sedums to inquiring gardeners in our community is practically a public service, given the low maintenance requirements of these nonetheless interesting plants and their ability to survive with little or no supplemental water.

“Drought tolerant” sounds very good right now, and few plants tolerate dry conditions as well as the more than 300 species of the Sedum genus native to regions in the northern hemisphere. Most sedums are perennials—there are a few annuals and biennials but they’re seldom offered for sale except by collectors—and most of them are fully hardy here. There is a sedum for just about every situation in the garden. They offer foliage from many shades of green to blue to purple, as well as several variegated variations. The foliage of some species and varieties transitions from one color to another over the course of a season. Flowers can be white, pink, lavender, purple, yellow, red, orange, bronze, or light green and are typically described as “starry.” Sedums come in all sizes, from mat-forming ground covers that never grow taller than an inch, to two-feet-tall mounds, to stands of flower clusters that top stems reaching 30 inches. Many of us are familiar with Sedum ‘Autumn Joy’—but don’t forget other varieties of “showy stonecrop,” including ‘Pink Chablis’, ‘Carmen’, ‘Purple Emperor’ and ‘Brilliant’. There are so many other sizes and colors that you’ll often find them in garden centers labeled simply as “assorted sedum.” Of the small-leaved types, what you see is true to what you get. The sedum you choose for a ground cover will stay that blue or that green. It will spread out but not up, and it will reward you with flowers during the late summer. Some of the low-growing varieties will bloom earlier, but the foliage remains attractive all season. The clumping sedums—including the purple-leafed ‘Vera Jameson’—are best cleaned up in late fall or early winter, but most gardeners choose to leave the flower heads on their showy stonecrop long after the first frost has robbed them of color. The dried blooms add more than a bit of visual interest to the late fall and winter garden.

Sedums are succulents, characterized by fleshy leaves to store the water they need to grow on. They also carry on some of their botanical activities at night. Consequently, they are very well adapted to thrive with almost no additional water, even during summers such as the one we’ve been gifted with this year. While many of them look incongruously tropical, they are actually very tough plants that accept whatever Mother Nature has to offer in the rainfall department—and they’ll make do nicely if she decides to withhold rain entirely. They are not susceptible to diseases and few pests pay any attention to them. I have seen slug damage on some showy stonecrops, although it seems half-hearted compared to what slugs can do to plants with more tender leaves. But what slugs leave alone, the butterflies and bees enjoy.

You can keep them well supplied; sedum is one of the easiest plants to propagate. Just break off a leaf or a bit of stem and poke it in the ground. Water it until it shows signs of new growth. Sedums will thrive so long as drainage is good and the sun is abundant. Deep shade won’t do, nor will soggy soil, particularly if it is very heavy. Sedums prefer some grit in their growing medium. They are known for performing well in scree gardens, in which plants are grown in crushed-limestone gravel. These are reputedly so forgiving of neglect that they’ve been called “one-hour-of-care-each-year” gardens, although whoever came up with that concept didn’t take into account the time and knuckle-bruising labor required to pry weeds out of gravel. They will appear, and they are difficult to remove. If you choose to take another route entirely and forego the gravel, plant your sedum alongside other perennials, feature it in a rock garden, or tuck it into chinks in a rock wall. You can grow it in a dish garden, or learn from Karen Gilliam how to use it to make a beautiful living wreath. According to folk wisdom, you can hang sedum on your wall in midsummer to ward off lightning strikes and use it to foretell the outcomes of affairs of the heart. It also is reputed to have medicinal benefits and to boost energy—although personally, I think I’ll stick to growing it as an ornamental rather than an edible. Goodness knows, there’s enough zucchini to fill all the plates I have—and I’ll happily resist the impulse to wash it down with sedum tea. I’ll leave that in the “don’t see it” category.