Succulents for the window garden

If you’re one of those people who’s daunted by the responsibility of caring for your plants, succulents are the perfect answer. These tough denizens of the plant world will put up with a good deal of abuse, especially when it comes to watering.

But for me, it’s their flowers — beautiful, bizarre or both — and unusual leaf structures (which sometimes make them seem like visitors from another world) that really set these plants apart.

All succulents, including cactuses, are xerophytes — plants that have adapted to an arid environment. They’re called “succulent” because they’ve developed thick, fleshy stems or leaves designed to hold water. Cactuses, however, are grouped in a single family, the Cactaceae — the only plants that produce an “areole” (a special spot on the plant that generates spines). Succulent, on the other hand, is not a family name but a term that applies to hundreds of different plants from all over the world. Any plant that stores water in its leaves or stems is a succulent.

The orchid cactus is wisely named because, like the fabled orchids, the flowers of this unusual member of the cactus family are among the most beautiful found anywhere in nature. The genus Epiphyllum derives its name from the Greek “epi” (meaning “upon”) and “phyllos” (“leaf”), because at one time botanists thought the flowers were borne on leaves. It turns out that the “leaves” are really flattened stems.

Although they’re true cactuses, epiphyllums are found not in deserts, as one might imagine, but mostly in the jungles of Brazil, Mexico, Costa Rica and Guatemala. They grow high up in the jungle canopy, where they find perfect drainage. Detritus caught in the bark of host trees and washed down by tropical rains feeds the roots of these unusual plants. Their main branches are woody, the green stems flat or thin with wavy margins. The typical cactus spines, missing on mature plants, are often present as bristles on seedlings or juvenile plants.

The older the plant, the more architectural it becomes, and the more blossoms it produces in early spring. Tiny buds appear between the scallops on the stems, growing visibly larger every day till they suddenly open into breathtaking flowers, aglow with vibrant colors: white, yellow, red, scarlet, and red streaked with iridescent purple. The texture of their petals resembles glistening satin.

Among the many spectacular cultivars available are ‘Argus’ (5-inch apricot-colored blossoms with a mandarin-rose center and a yellow throat); ‘Climax’ (large, off-white petals with light lavender central stripes and outer petals of a progressively darker amethyst that changes to red); ‘Fireball’ (7- to 9-inch-wide, satiny-orange flower with overtones of pink, plus a yellow-green throat and pink anthers and pistil); and ‘Morocco’ (whose flowers combine orchid-purple, red, yellow, regular purple and cream, the two outer rows of petals having yellow bases and becoming progressively darker).

Orchid cactuses are adaptable plants. During winter dormancy, they can survive temperatures as low as 40 degrees Fahrenheit without damage; freezing, however, will kill them. And though direct sun in summer can burn the stems, these plants will do well in filtered sun to bright shade. They should be watered well in their active growth phase and allowed to be dry during winter. But when the stems begin to shrivel, water as fast as you can.

Perfect drainage is essential; I use equal parts potting soil, peat moss and sand, placing the plants in hanging baskets lined with sphagnum moss. Fertilize once a month from April through September. And if possible, hang the cactuses in a sheltered spot outdoors — under a tree or on the front porch — during the summer months.

Peter Loewer is a freelance writer based in Asheville.