By Jeanne O’Brien Coffey
Nature will find a way. From dandelions pushing through a crack in the pavement to an eastern red cedar clinging to a rocky ledge, plants are driven to survive despite the odds.
Crevice gardens—landscapes that depend less on water and more on rocks—rely on those survivors to beautify rugged spaces and thrive with little human intervention. As water conservation and the changing climate become critical concerns for horticulturists and home gardeners alike, these sustainable and stunning designs are trending across the country.
“Crevice gardening, and water-wise gardening on the whole, are increasingly popular styles in which gardeners work with, instead of against, natural hardscapes and ecological microclimates,” says Hadley Mueller at High Country Gardens, a mail-order specialist in plants for sustainable gardening.
An extreme iteration of a classic rock garden, crevice gardens are purpose-built to allow only tiny spots in or between rocks for plants to grow. Mueller says these features are part of a larger sustainability story in the industry because, like most rock gardens, they are relatively low-maintenance and demand less water, since the rocks help divert water or snowmelt to plants’ roots.
You don’t need a rocky outcrop in your backyard to explore the technique, says master gardener Molly Janicki, whose Massachusetts-based business Molly Janicki, Horticultural Services, is devoted to working with native features to create beautiful, sustainable ecosystems. At its simplest, she says, you can start a crevice garden by sprinkling some bluet seeds in the cracks of your patio. “I see crevice gardening as part of a larger trend of observing plants more,” she says. “Crevice gardening is finding the little niches where plants will grow, which is just recognizing that plants will grow everywhere and anywhere that we give them the opportunity.”
In New England, which is blessed with rich soil and rarely experiences the extreme droughts seen in other parts of the United States, purpose-built crevice gardens have yet to take hold, Janicki says. But it might just be a matter of time, notes Kenton Seth, who wrote the 2022 book The Crevice Garden, a practical how-to for jumping aboard the trend, with coauthor Paul Spriggs.
“Crevice gardens are oddly universal, though they seem to resonate first with people in areas where it is naturally rocky,” says Seth. “Coastal and mountain settings already have a rich rock-work culture to grow from.” Not surprisingly, Colorado has been a trendsetter in purpose-built crevice gardens for almost a decade, he adds, with California close on its heels.
Gardeners who want to go for that rocky drama can start small by just burying some stones standing together, Seth suggests. “Don’t be afraid to mess up, and allow yourself ‘sandbox playtime,’ ” he advises.
You can even use cinder blocks and other recycled materials, says Daniel Feldman, senior manager of horticulture for the Natural History Museum of Los Angeles, which hosts a spectacular crevice garden in its Nature Gardens. “Look to nature for inspiration. See what grows on those steep slopes and in rocks,” he adds, noting that some of his favorite crevice gardens occur naturally—the Hanging Gardens in Zion National Park, Fern Canyon in Prairie Creek Redwoods State Park, and the rocky peaks of the Santa Monica Mountains.
The museum’s Living Wall crevice garden is home to dozens of plants that actually prefer growing out of a vertical surface—a trait that lends itself well to a small space or use as a divider, Feldman says. “As a space- saving strategy it opens a whole realm of possibilities,” he explains. “Though it might be costly or time-consuming to construct, it’s a very unique type of garden and could be done in a relatively small space.”
If you’re thinking of adding a wall garden to your property, be aware that the building style is still relatively new, and it requires technical expertise
to ensure that the wall won’t collapse as the roots grow, Seth cautions. You’ll need to hire someone with experience, even if that means searching outside your local area, he notes. It’s also important to work with contractors and builders who “have an eye for aesthetics,” he says.
As water restrictions become the norm, more and more people are likely to open their minds to crevice gardening and to develop expertise in areas such as wall gardens. The crevice garden concept is “ideal at this moment in history, when everyone is looking towards ecological solutions to everyday problems—less water, fertilizer, and money, all while honoring the landscape itself,” says High Country Gardens’ Mueller.
Creeping phlox is a classic rock garden plant that flourishes in hot, dry, sunny spots and works well along sidewalks and driveways. Toss bluet seeds in the cracks of your patio to yield a profusion of small, delicate blue flowers. Other good bets are sweet fern (sweetly scented with fernlike foliage though not a true fern) and eastern red cedar, a native evergreen loved by birds and able to handle a wide range of conditions. Best of all? It thrives on neglect.
Opt for succulents that grow well in tiny, sloped spaces with rocky soils, where excess water drains off easily. These include chalk lettuce, Santa Catalina live-forever, lady fingers, California fuchsia, Baby Rita, chandelier plant, Graptoveria, and blue thistle. You might also try California buckwheat and indigo bush, both trailing plants that cascade beautifully over the tops of walls.
Plants like cold-hardy cacti, hens and chicks, and other low-growing, low-water (xeric) ground-covering plants with deep taproots that help in stabilization are ideal. Larger-growing xeric plants like hummingbird mint, lavender, sundancer daisy, beardtongue, and native sage work well too.