Sedum - Stonecrops   Linnaeus (1757)

Sedum is a large genus of over 400 species distributed through the Northern hemisphere. Most species are succulent, varying from mat-forming stonecrops to small shrubs. A few species are annuals or biennials.
 
Several species have been moved from Sedum to the Genus Hylotelephium including the colourful H. telephium and H. spectabile (Autumn Joy). These plants have large, flat leaves with serrated margins. The inflorescence is typically a dense head of tiny pink flowers.
The British native plant, formerly Sedum rosea (Roseroot) has been moved to the Genus Rhodiola.
 
Many Sedums are frost-hardy and suitable for a sunny garden. The water-retaining properties of Sedum leaves allows them to be used as drought resistant plants. Creeping stonecrops can be planted in cracks in paving and tolerate being walked on occasionally. Any bits that break off will likely find a crack to root in.
 
In some countries, mat-forming Sedums have been used as green roof coverings, a trend that seems likely to continue. Ready-grown mats of mixed hardy Sedums are grown commercially for this purpose. Many Sedums are recorded outside their natural range, potentially invasive and could displace native species.

In Great Britain, Sedum acre ( Biting Stonecrop ) may be found growing in short grassland from the South Downs to Nothumberland, above the high tide mark on beaches and among rocks. This hardy species is native to the Balkans and Asia Minor but has become naturalised over much of Europe and elsewhere. S. acre contains piperidine alkaloids, making it toxic or at least irritating to herbivores. In traditional medicine, it has been used as an emetic.
 
The stems of S. acre produce white aerial roots which root down into the substrate as they spread. Quite short stem fragments can develop into a new plant. This species is easy to propagate and grows and flowers fairly freely in a well-drained sunny location.
Left: S. acre on the beach near Littlehampton, West Sussex, UK.

Sedum album is a larger, more robust plant than S. acre with a similar origin and distribution across Europe and the Great Britain. It is easy to propagate from a piece of stem and spreads rapidly to form dense mats in the garden. It is liable to over-run other more delicate sedums, but its vigorous growth makes it suitable for difficult locations, gaps between cracks in paving and green roofs.
 
Left: S. album on the beach near Littlehampton, West Sussex, UK. Despite growing in close proximity to S. acre and flowering at the same time, the two species appear to remain distinct. From their location, one has to assume that these stonecrops are salt tolerant.

Sedum diffusum (Syn. Sedum potosinum) is a mat-forming plant growing on limestone soils of the Eastern Sierra Madre of Mexico. The older leaves are glaucous blue on pink stems. Flowers are white, produced in mid-Summer. Not frost hardy but an attractive plant for a patio planter if winter protection is available.
 
The synonymous name "Sedum potosinum" commemorates its occurrence in San Luis Potosi.

Sedum havardii (Havard's Stonecrop) growing in the Chisos Mountains, Texas. The creeping red stems with upright sections carry clusters of green to glaucous green, narrow leaves towards their ends and greenish to pinkish flowers with 5 petals.
 
Sedum havardii is native to oak and pinyon pine woodlands of Texas and Mexico, growing on igneous soils at elevations of 4500 - 7500 ft.

Sedum hispanicum (Spanish Stonecrop) is a tiny, almost mossy mat-forming plant with glaucous blue leaves which can take on a pink tinge when stressed. The white to pale pink five-petalled flowers are produced in early Summer. It spreads freely from small cuttings and will tolerate being walked on occasionally.
 
Sedum hispanicum is fully hardy in Great Britain but native to Southern Europe and prefers full sun to light shade. It is quite drought tolerant. Several named cultivars are available through the horticultural trade, selected for extreme blue, pink or other leaf colours.

Sedum lanceolatum (Spearleaf Stonecrop) is a widely distributed plant of dry, gravelly hillsides and mountains as far North as Alaska , Canada and South to California, Colorado, Utah, Oregon, Nebraska and the Dakotas of Northern America. Dense rosettes of succuulent, grey-green lance-shaped leaves which become reddened in full sun. The erect flower stems bear heads of relatively large bright yellow star-shaped flowers with five petals.
 
Sedum lanceolatum requires well-drained soil in full sun or partial shade and is frost hardy, growing at over 12,000 ft in the Rockies. However, it is rarely seen in cultivation. Traditional use has been made of this plant as a laxative.

Sedum pachyclados (Syn. Rhodiola pachyclados) is a choice plant from the mountains of Pakistan and Afghanistan where it grows at altitudes of 8000 - 11,000 ft. It forms a dense hummocks of small, tight rosettes on short stoloniferous, stems. Leaf tips are distinctively three-toothed. Small white starry flowers are produced during early and late summer.
 
Sedum pachyclados is fully cold, wet hardy through the English winter, yet remarkably drought tolerant. A good choice for the rock garden or as a potted specimen. Various selected cultivars are available with foliage in different hues.
Left: Seen here at RHS Wisley.

Sedum praealtum (Siempre Viva, Mexican Bush Sedum) is a large hardy Sedum from Mexico, growing as a 3 ft bush. The flower heads of tiny but bright yellow flowers are produced in late Spring. The stems are quite brittle and in my garden perching birds regularly break off new "cuttings". It is a good subject for a patio planter with its fleshy leaves making an exotic succulent appearance in a temperate garden.
 
S. dendroideum is a similar bushy plant, with leaves which widen markedly near their tips and have sub-epidermal glands along the leaf margins. These glands tend to redden in full sun.

Rhodiola rosea Syn: Sedum rosea ( Roseroot )
is a clumping hardy perrennial, native to the highlands of Scotland and to Norway. Other forms come from Northern Eurasia and North America. The glaucous-blue fleshy leaves have toothed margins. Decorative heads of bright yellow to white flowers in late Spring to early Summer make this an attractive plant for the rockery. The plant dies down in winter to a woody rootstock on the surface of the ground.
 
Requires excellent drainage, but otherwise undemanding. A magnet for Vine Weevil larvae. Roseroot has been used as a herbal medicine for thousands of years, said to improve energy, stamina, memory and manage stress.

Sedum rubrotinctum has small, glossy, bead-like leaves that take on a reddish hue in full sun. In a climate with very strong sun this Sedum needs light shade. Leaves tend to drop off the sprawling stems and root to form new plants but stem cuttings can also be taken. The leaves are considered poisonous if ingested and their sap may irritate the skin. Heads of yellow flowers, with reddish sepals in strong light, are produced in the Summer.
 
Native to Mexico and not frost-hardy. This is a plant that will grow for anyone and makes an attractive window-ledge plant.

Sedum rupestre (Syn. Sedum reflexum) (Stone Orpine) is a prolific, hardy mat-forming plant with fine, needle-like gray-green leaves packed around the reddish-brown stem and clusters of bright yellow star-shaped flowers in the Summer. New plants can be readily produced from stem cuttings. Native to central Europe but naturalised in many temperate countries.
 
S. rupestre (Stone Orpine) is considered edible as a salad ingredient or added to soup.
Left: Sedum rupestre c.v. angelina is an attractive cultivar with golden foliage, especially when grown in full sun. Cultivars selected for especially blue foliage and cristate growth are also available. Both the normal and golden forms make exellent ground cover, even on my heavy clay soil.

Sedum rupestre is a very similar species to Sedum rupestre, native to Southern Great Britain and Europe. The lower stems of Sedum rupestre are felted with persistent old dead leaves, thus distinguishing this species from the more robust Sedum rupestre which has no dead leaves below the terminal clusters of live leaves.

Sedum sediforme (Mediterranean Stonecrop, Pale Stonecrop) grows as mats of erect reddish stems with blue-green fleshy leaves along the stems. The plants adopt a red colouration in full sun or when stressed. The inflorescence is a panicle of bright yellow flowers, produced in the Summer.
 
Sedum sediforme is fully hardy in Great Britain, although native to countries bordering the Mediterranean. An excellent plant for a dry rockery. This species is tolerant of soils contaminated with copper and has been investigated for cleaning up contaminated land and for controlling soil erosion.

Hylotelephium (Sedum) telephium from Eurasia provides useful flower colour in the garden in late summer and early autumn. Dense heads of many tiny pink, red or white flowers are produced in late Summer and Autumn, attracting bees and butterflies. The flat buish-green leaves have serrated margins and provide a spectacular contrast to the flowers. These tolerant plants are fully frost hardy, but the stems die down to the ground each year after flowering.
New plants may be propagated from stem cuttings. If the growing stem is pinched out early in the season, it will branch to form multiple flower heads and the pinched tips can be used for propagation.
 
H. spectabile is a similar hardy, free-flowering plant. Numerous Hylotelephium hybrids and cultivars are available for the garden, with a range of flower colours from white to deep red and in some cases coloured leaves in shades of purple.

Sedum wrightii (Wright's Stonecrop) growing in fissured wet rocks near a natural spring in the Chisos Mountains, Texas. These micro-habitats provide some shelter from the harsh climate and the scorching sun. The branching stems carry rosettes of leaves from which arises an attractive inflorescence with 10 - 30 white to pale pink tubular flowers.
 
Sedum wrightii is native to Texas and New Mexico. Some authors consider S. wrightii to be synonymous with S. cockerellii.

Sedum sp. growing in the San Bernardino Mountains, California.
Flowers were typical white stars with five petals.