Top Succulents for Sonoma County
Compiled by SCMG Anne Lowings Edited by Rosemary McCreary & Sara Malone
Succulents are a group of plants whose distinctive features evolved to reduce water loss and to withstand long periods of drought. These various species have the ability to store large amounts of water and food in spongy tissue in their leaves, stems, or roots, which they release when needed. Basic culture is the same for all succulents. This includes good drainage, deep but intermittent watering (allow soil to dry out between waterings), bright light/full sun, and good air circulation. They grow best in an open and airy soil relatively low in organic matter. Cold, waterlogged ground in winter generally presents the biggest challenge for succulents here in Sonoma County where they do best when planted on a slope or on top of mounded soil.
The plants in our selection are chosen for their hardiness to 20°F. There are many other wonderful succulents that are frost-tender but can be grown in pots and moved to a sheltered area in winter. When buying succulents, always check labels for cold hardiness.
Agave (Century Plant)
These sculptural plants bear fleshy, rigid leaves arranged in rosettes, usually with a sharp terminal spine and toothed margins. Once the rosette is mature, which may take many years, an impressive flower stalk emerges from the center bearing creamy white, yellow, or green funnel- shaped flowers. In most species, rosettes die after flowering, leaving the offsets to mature and flower in subsequent years. There are many relatively small agave species that make wonderful design accents in the garden.
A. filifera (thread-leaf agave). Rosettes are 2-3 ft. wide with dark green, bayonet-shaped leaves lined with long, white, threadlike filaments that curl from the edges and glow when backlit. 'Compacta' has rosettes only 6 in. to 1ft. wide.
A. parryi (mescal or artichoke agave). A beautiful pale blue species that thrives in part shade. Its thick leaves have curved teeth along margins and are tipped with sharp grayish brown spines. Leaves form a compact rosette 2-3 ft. high. Each leaf bears an imprint of the leaves that unfurled from the center before and after it. A. neomexicana is similar but paler in color with slender and longer black spines. A. colorata has broader powder blue leaves.
A. victoriae-reginae (Queen Victoria agave). Regal-looking and compact, this agave is very slow growing, making it an ideal candidate for decorative containers. Rosettes are 18 in. to 2 ft. tall and nearly twice as wide. Short, stubby, dark green triangular leaves are dramatically edged in white. Leaves have smooth margins that end in short, needle-sharp spines.
A. striata and A. stricta (hedgehog agave). These species look quite different from other agaves. Their narrow, gray-green, knitting-needle-like leaves form colonies of pincushion rosettes. A. stricta rosettes grow in a slightly different direction creating a feeling of movement within each colony.
Aloes come in all shapes and sizes from stemless miniatures to large trees. Most are excellent choices for container plantings. Differing from agaves whose leaves unfurl, aloe rosettes are formed as fleshy, pointed leaves grow from the center. Leaves may be banded or streaked with contrasting colors and can become suffused with red in poor soils and arid conditions. Long flower stalks bear clusters of red, orange or yellow tubular blooms. Many species flower in winter or early spring.
A. nobilis (gold-tooth aloe). Fleshy, dark green leaves in rosettes form a compact clump by producing many offsets. Leaves are covered with pale prickles that glow when backlit; 2-ft. flower stalks carry reddish orange tubular flowers in midsummer. Suitable for mass plantings and edgings.
A. striata (coral aloe). Smooth gray-green leaves lined with coral-pink have spineless margins and form short stemmed rosettes 2 ft. wide. When grown in full sun, foliage is pinkish, but in cool spots is bluish green. Coral-orange flowers are borne on branching flower stalks in midwinter to spring.
A. ‘Johnson’s Hybrid.' Narrow, bright green, white-spotted leaves with small teeth along the margins form dense clumps 1 ft. high and 2 ft. wide. Bright orange flowers on 1-ft. stalks keep coming throughout the year. Excellent rock garden choice and companion to Mediterranean plants.
A. polyphylla (spiral aloe). Stemless, solitary rosette to 1 ft. tall and wide. Leaves spiral outward in a beautifully patterned pinwheel. Leaves are triangular and bear short spines on tips and margins. Best in cool microclimates with part shade (thirstier than most other aloes). Blooms only in maturity. Plant where may be viewed from above to appreciate spiral growth pattern.
These shrubby succulents are grown for their handsome foliage and colorful flowers. The stalked, paddle-shaped leaves are borne in opposite pairs forming a compact clump. Flowering usually occurs in late summer and autumn. Flowers are tubular to bell-shaped with curled tips producing copious amounts of nectar that attracts aphids. Easily propagated from cuttings.
C. orbiculata (pigs ears). Leaves are large, round, thick and fleshy, varying from bright green to gray to silver-white as result of surface wax. Frequently they are edged in crimson. Rapidly grows to 3 ft. tall and 2 ft. wide. Flower stalks hold orange-yellow, drooping flowers 2 ft. above the leaves. Looks good in most landscapes and does very well as a container plant. C. orbiculata var. undulata is smaller to 18 in. high. Leaves have a delicate silvery bloom and ruffled margins.
Thick woody stems bear clumps of narrow grass-like leaves that can shimmer and sway in the wind creating a dramatic statement in gardens. With great age, some species develop trunks up to 10 ft. tall. Male and female flowers, borne on separate plants, appear along tall spikes in summer and resemble pipe cleaners.
D. longissimum (Mexican grass tree). Spherical clump of dull green, toothless leaves up to 5 ft. long emerge like a fountain from the trunk, which with age may reach 10 ft. tall. White bell-shaped flowers open from red buds along the narrow flower stalk. Old foliage can be trimmed to reveal the attractive trunk. An excellent specimen plant, safe to plant near walkways.
D. texanum (green desert spoon). Neat, rounded clump formed by narrow, glossy, dark green leaves with small, sharp, marginal teeth. Small white flowers attractive to hummingbirds appear on the flower spike, which may reach 8 ft.
D. wheeleri (desert spoon, sotol). Twisted and curled blue-gray leaves form a nearly spherical clump. Leaves have hooked spiny margins that are dangerous when planted near walkways. An exciting specimen for a container. In the ground, the trunk can reach 3 to 4 ft. with great age.
Delosperma (Ice Plant)
This Mediterranean-climate succulent forms shrubby mounds or lush mats with fleshy, rich green, cylindrical leaves covered with glistening water-storage cells; hence, the common name of ice plant. Showy, daisy-like flowers appear in spring and sporadically all year until frost. All do best with regular water in summer.
D. cooperi (hardy ice plant). Forms a heat, drought, and salt tolerant mat 3-6 in. tall, 2-3 ft. wide that makes a great ground cover and filler for slopes. Vibrant purple-pink flowers appear all summer.
D. nubigenum (yellow ice plant). Only 1 inch tall and spreading to 2 ft. wide to form a solid mat. Leaves turn red in winter and green up in spring. Bright yellow flowers cover plants in late spring. Looks good cascading over retaining walls.
These West Coast natives form low-growing, dense rosettes of ovate-linear leaves with pointed tips. Rosettes may be on prostrate stems or form clumps. Flowers borne on vertical or inclined stems are star-shaped, colored yellow, white or red. Water very little or not at all in summer when dudleyas are dormant; they do most of their growing in late winter.
D. farinosa (bluff lettuce). Native to Northern California coast. Centers of rosettes have blue-gray leaves covered with powdery wax; outer leaves turn bright red when low in water. Yellow flowers develop on red stems May to September.
D. brittonii (giant chalk dudleya). Best known species in cultivation; however, growing can be difficult due to need for perfect drainage and protection from frost, rain, and intense sunlight. Chalky grayish white rosettes form on leaning or prostrate stems. Produces masses of green yellow flowers on 3-ft. stems when flourishing. Can look stunning in niches of rock walls or in pots.
Small rosettes ranging in size from 1-2 in. to 2 ft. across multiply rapidly to produce offsets that form compact clumps. Valued for their amazing colors and variation, leaves may be green, blue, red, purple, or brown and may develop brilliant tones in cooler months. Long-lasting, showy bell-shaped flowers rise on arching stems in summer. All forms prefer good air circulation and bright shade rather than full sun.
E. agavoides ?Lipstick.' Dense rosettes of fleshy, stiff, pointed leaves. When planted in bright enough light, the chartreuse leaves turn crimson along the edges. Compact, ground hugging, and beautiful in rock gardens and mixed succulent beds.
E. hybrids. These cultivars generally have large loose rosettes of big leaves, which may be crimped, wattled, or ruffled and may be less tolerant of extreme temperatures. They become splendid specimen plants in pots. ‘After Glow’ has powdery, pinkish lavender leaves with ruffled margins that create most attention when flowers are removed. Short, close-set leaves on 'Doris Taylor’ are edged in red and covered with soft white hairs. 'Black Prince' has dark chocolate colored leaves that contrast with salmon-red flowers in late autumn.
Graptopetalum (Ghost Plant)
This species resembles echeveria with its pointed leaves that form compact rosettes along branching stems. Leaves vary in color from grayish green to lavender pink with reddish margins and are often covered with a powdery film. Plants prefer bright light but may scorch in hot sun. Can be used as ground cover in areas that receive no foot traffic or in rock gardens and hanging baskets.
This intergeneric hybrid develops rosettes similar to Echeveria and yellow-to-pink flowers similar to Graptopetalum and is cultivated for beautiful shapes and varied colors. Easily propagated from leaf cuttings.
Sedum (Stone Crop)
Different types of this popular succulent vary in size and shape from fine-leaved ground covers only 2 in. in height to shrublike border plants, which can be 2 ft. or more. Starry, brightly colored flowers are borne in stemmed clusters in late summer.
S. ruprestre 'Angelina.' Brilliant chartreuse-yellow, needlelike foliage turns rust red in winter to form a striking ground cover.
S. spathifolium. Vigorous, mat-forming, evergreen perennial 4 in. high and 2 ft. wide with grayish green spoon-shaped leaves on trailing stems. Excellent edging plant. ?Cape Blanco' has silvery powdered covered leaves. ‘Purpureum’ has deep purple foliage.
S. spurium. Ground-hugging succulent with trailing stems and small dark green, bronzy leaves about an inch long. Pink, white, or purple flowers in dome-shaped clusters in mid-summer. ?Dragon's Blood’ has red-margined green leaves that become brilliantly red with cool autumn temperatures. ‘Bronze Carpet' bears rich bronze-red foliage with pink flowers. ‘Tricolor’ leaves are variegated in green, creamy white, and pink.
S. telephium. ?Autumn Joy' grows 2ft. tall and wide with bright green leaves on upright stems. Long blooming, plate-like flowers attract bees as they change from pink to bronze throughout 3 seasons. Looks good with ornamental grasses. 'Matrona' has gray-green leaves edged in dark pink and large heads of pink flowers borne on red stems. Both cultivars look better with regular water in summer, and both die to the ground in winter.
Small, hardy alpines form neat rosettes of tightly packed, pointed leaves that come in a wide variety of forms colors and textures. All spread by little offsets on slender stems that nestle around the mother plant. Small, star-shaped flowers arise on fleshy stems up to 10 inches tall. After flowering, the central rosette dies and offsets live on. Good in rock gardens, crevices in walls and pots. Give plants excellent drainage and light shade in hot summer climates.
S. arachnoideum (cobweb houseleek). Gray-green rosettes of many leaves. Long hairs join the leaf tips to form a perfect white cobweb over each rosette. Spreads slowly to form a dense mat 1-foot or more across.
S. tectorum (hens and chicks). Open rosettes 2-5 ins. across spread quickly to form clumps 2 ft. or wider. Leaves are gray-green with red-brown bristly tips. Many colored-leaf varieties are available: 'Atropurpureum' is dark violet; 'Limelight,' chartreuse with pink tips; ‘Atroviolaceum,' violet with metallic sheen.
All have tough bayonet-shaped leaves arranged in stemless clumps or on trunks that can reach tree size. The bloom stalks are massed with waxy cream-colored, bell-shaped flowers. Use as architectural specimens in borders, courtyards, or containers.
Y. aloifolia (Spanish bayonet). Single or branching trunk grows slowly to 10 ft. Narrow, dark green leaves 2 ft. long have very sharp tips. Dramatic flower stalk bears white flowers in late spring/summer. Do not plant near walkways or other well travelled areas.
Y. filamentosa (Adam’s needle). Develops a rounded sphere of bluish green leaves from a broad base. Curly threadlike fibers peel off leaf margins. 'Bright Edge’ has green centers with gold leaf margins; 'Color Guard' has bold center stripe of canary yellow.
Y. flaccida (weak-leaf yucca). Resembles Y. filamentosa; however, leaves are narrower and less stiff, lower leaves become quite lax and curve downward. Grows to tree size with age; several rosettes may form a small colony. 'Garland's Gold’ and 'Gold Sword' bear 1 to 2 in-wide leaves with golden yellow centers and dark green margins.
Y. pallida (pale yucca). Dramatic 18 x18-inch rosettes with flexible, silvery blue leaves that arch gracefully and drape with age. Trunkless, but can eventually form a wide clump with up to 30 heads. A good choice for locations where a low-growing form is needed. Use in shade garden for textural interest.
Succulents are available at many nurseries throughout Sonoma County, such as Lone Pine Gardens (succulent specialists) in Sebastopol, Cottage Gardens in Petaluma, Emerisa Gardens in Santa Rosa and Sonoma Mission Gardens in Sonoma.