Sedums are low maintenance, durable and interesting. They enhance the appearance of green roofs, vertical walls and rockeries due to differing leaf forms, flower colours and extended flowering period. If started early, they will form a dense ground cover in the very first season and if the weather is favourable, will flower within six months.
Sedum glaucophyllum ‘Silver Frost’ is a charming species that grows on lightly shaded, limestone rock layers in the Appalachian Mountains in the eastern United States. Easily established from seed, this perennial is commonly called Cliff Stonecrop.
This prostrate, mat-forming evergreen perennial plant that will create a carpet, creeping along the ground's contours. It will grow to only 8cm (3in) in height but will spread 30 to 45cm (12 to 18in) in diameter. The attractive succulent foliage forms rosettes of tiny, blue-green leaves. The leaves are rounded, 1 to 2cm (½ to 1in) long and wide, arranged in a dense spiral on the stems.
In late spring the plants come alive with tiny spikes of white star shaped flowers each with contrasting purple anthers. The flowers are 10 to12mm (½in) diameter, each with five slender, pointed petals. They are produced in clusters on erect stems 10 to 15cm (4 to 6in) tall, held above the foliage.
In its native habitat, Sedum glaucophyllum grows on lightly shaded limestone outcrops where it is regularly damp but very well-drained. Extremely hardy they can cope with temperatures down to minus 34°C. (-30°F) and are evergreen in areas with milder winters.
These alpine selections are particularly good for hot, dry sites with poor soil, they make good ground cover plants and are excellent for gren roofs and vertical wall gardens. They can be used for edging a pathway or for the rock garden where they can be can grown around rocks or anchored into crevices of walls.
Suitable for alpine gardens, troughs and pots, Sedum glaucophyllum ‘Silver Frost’ is a worthy addition to any succulent collection.
Sowing: January-March or June-August for flowering the following year
Seeds can be sown in spring or late summer at temperatures around 10 to18°C (50 to 65°F). Cold temperatures (10°C / 50°F) will increase the cultivation time. In spring the plants start to grow at 15 to 18°C (60 to 65°F).
Sowing Direct: For a Green Roof or Rockery
Prepare a fine weed free free-draining bed. Mixing seed with fine sand will aid even distribution. Sow seed evenly over the surface. Gently rake the seed bed so the seed comes into contact with the soil mix and gently water in. For green roofs, use a soil mix specifically for the purpose. For wintering the root development should be very good, small seedlings need to be frost free at around 3 to 5°C (37 to 41°F) so if you are growing seedlings through the winter outdoors, outdoor fleece cover will be needed to keep them frost free.
Sowing Indoors: In Pots
Sowing directly into small pots is recommended. Use seed spoons if you have them or mix the fine seeds with fine sand to aid even distribution. Fill pots with an acid-free, free-draining soil seed compost. Tap the pot to settle the compost, but do not firm the mixture down. Stand the pots in water, moisten thoroughly and drain. Seeds should be scattered very lightly over the surface.
Sedums require light for germination. Cover seed lightly with vermiculite after sowing.
If possible, place in a propagator otherwise, secure a polythene bag around the pot or cover the container with glass or and place in a warm place. Many people make use of a warm place such as the airing cupboard, or near the kitchen boiler. Care should be taken to prevent the pots drying out from below. Keep soil slightly moist but not wet. Some people stand the containers on a tray of damp sand, so that they do not dry out.
The seeds germinate best at temperatures of 18 to 22°C (65 to 72°F). Most seedlings appear within 14 to 21 days.
Be careful to keep the top of the compost damp but not wet. As soon as the first seeds have germinated, remove the plastic or raise the lid slightly to permit circulation of air.
Six to eight weeks after sowing transplant or thin out to 1 to 3 plants into a 9 to 10 cm pot or about 3 to 5 plants into an 11 to 15 cm pot. Avoid very large pots, because the substrate in pots that are too large will be permanently wet and wetness can cause growth inhibition and a poor root development.
Sedum tolerates high temperature and dryness, but the roots are very sensitive to wet substrates. Plant in acid-free free-draining soil in a sheltered, sunny position.
Low to moderate fertilization levels are required. Use a complete balanced fertiliser, avoid high ammonium and high nitrogen levels. (Very high nitrogen levels in substrate cause shoot stretching and the shoots fall apart). Don't fertilise after mid September.
Beds and borders, City, Containers, Cottage/Informal, Drought Tolerant, Gravel, Ground Cover, Low Maintenance, Rock Gardens, Green Roofs.
Sedums look good in containers and in combination with other succulents such as sempervivum, echeveria or stonecrop. You can also display them with other low growing plants such as mosses, ajuga, or creeping thyme..
Sedum for green roofs or vertical walls:
Green roofs generally use sedum and other alpines to provide a natural finish to a roof. Sedums are at home in poor soil and have drought-tolerant capabilities that are second to none. The plants are very hardy, and can withstand great ranges of temperature and weather.
Sedums are able to close off their pores in the presence of hot, bright sunlight, and at night, open up to put out oxygen and breathe in carbon dioxide.
The plants have roots that are between 7 to 10cm (3 to 5in) deep. They do not need mowing, weeding or deadheading. During the spring and summer they will flower and attract many insects especially bees and butterflies.
Native to the Appalachian Mountains in the eastern United States from West Virginia, Maryland, Virginia and North Carolina. It grows on lightly shaded limestone outcrops where it is regularly damp but very well-drained.
The genus name Sedum is derived from the Latin word sedo meaning 'to sit'. This refers to the manner in which some species of this genus attach themselves to rocks and walls and stony ledges.
The species name glaucophyllum derives from the Greek word glauca meaning glaucous, it refers to the bluish-gray colour of the foliage.
Several sedums are associated with love, marriage and fertility. The association with love and marriage is shared with sempervivum believed to enhance the fertility of women & the sexual potency of men, so that many love-spells involved the use of stonecrops or hens & chicks. This isn't actually likely; as some sedums have phytoestrogens that could lower male infertility, but it's not inconceivable it also retarded male aggression & so indeed made couples more compatible in mood.
There was an associated belief that if evergreen succulents died either in the heat of summer or wetness and cold of winter, this meant the health of a household, or the success of a marriage, was at risk; if it kept its evergreen presence year-round, the household would experience continuous compatibility and good luck.
- Additional Information
Packet Size 10 mg Average Seed Count 250 Seeds Seeds per gram 25,000 seeds per gram Family Crassulaceae Genus Sedum Species glaucophyllum Cultivar Silver Frost Synonym Sedum nevii Common Name Syn. Sedum nevii Hardiness Hardy Perennial Hardy -34°C. (-30°F) Flowers White star shaped flowers Natural Flower Time May to August Foliage Silver green Height Plants 8cm (3in) - Flower stems 10 to 15cm (4 to 6in) tall Spread 30 to 45cm (12 to 18in) Aspect Some shade needed in hot areas. Soil Free-draining Time to Sow January-March or June-August for flowering the following year Germination 14 to 21 days at 18 to 22°C (65 to 72°F)