Above: Sansevieria cylindrica (left) and Sempervivum ‘Oddity’ (right) in an undersea-themed terrarium. Haworthias and sansevierias need much less light than other succulents and make good indoor or shade plants.
Cultivate succulents native to arid climates (which is the majority) outdoors during warm, sunny months and shelter them indoors during cold, wet months.
Water thoroughly but infrequently. Waterlogged roots may rot. Don’t use pot saucers. Let soil go nearly dry between waterings. The fatter the succulent, the more camel-like, and the less water it requires. Cacti in particular cannot tolerate overwatering. In winter most succulents go dormant; withhold water unless days are unseasonably warm.
Soil: Succulents are unfussy about soil providing it drains well. Amend garden soil and potting mixes 1/3 to 1/2 with perlite or pumice, or use a commercial cactus mix.
Food: Lightly fertilize (half-strength liquid fertilizer) in spring.
Sun: Give at least three hours of full sun daily, indoors or out, to maintain plant symmetry and color, and to encourage flowering. Protect from intense afternoon sun in summer.
Air circulation is important to prevent insect infestations. Watch for mealy bugs in leaf axils and aphids on flower buds. Control by spraying with dilute rubbing alcohol.
Temperature: The majority of succulents are frost-tender. Although they can tolerate temps down to freezing and in excess of 90 (if shaded), between 40 and 80 degrees is ideal.
Overwinter indoors. Echeverias and other rosette succulents are shallow-rooted and can be scooped from garden beds and packed into nursery flats. Provide six hours of light (fluorescent is fine and economical) daily to prevent stretching ; store between 35 and 60 degrees; and keep a fan running for air circulation. In spring, reintroduce to strong sunlight gradually lest leaves sunburn.
Most succulents dislike being cold and wet, but these can handle Pacific Northwest winters, rainfall (if given excellent drainage) and dry spells:
Sedum sieboldii, variegated
Sedum (stonecrop) — Trailing varieties are lovely as groundcovers, and in rock gardens, terraces and hanging baskets. Larger-leaved Mexican sedums (such as burro tail) are less tolerant of damp cold and should be overwintered indoors. Shrub sedums die back in winter and return in spring. All produce clusters of star-shaped blooms.
Delosperma (ice plant, above) – These cold-hardy groundcovers have satiny, daisylike flowers in brilliant hues of pink, orange, red, yellow, purple and combinations thereof.
Sempervivum (hen and chicks) — Resemble echeverias but rosettes have thinner, pointed leaves and a more compact, spherical form. Cobweb houseleek (Sempervivum arachnoideum, above) is webbed with white filaments. A similar genus is Jovibarba.
Valerie Easton’s Seattle Times gardening column, “Surprise! Some succulents succeed in Seattle” recommends my book, Succulents Simplified, and shows these photos: