Sedum, 'Roof Garden Formula Mix'

The Sedum Roof Garden Mix is a special formula mixture of many important varieties especially suited for green roofs. Representing a wide range of foliage types and flower colour range they are extremely hardy and many can cope with temperatures as low as minus 34°C. (-30°F)
Harvest permitting the mix includes:
Sedum album, forsterianum, hybridum, floriferum, ellacombianum, selskianum, pulchellum, reflexum, montanum, sexangulare, acre, spurium and others.

Sedum are low maintenance, durable and interesting. They enhance the appearance of green roofs and rockeries due to differing leaf forms, flower colours and extended flowering period. These drought-tolerant succulents are hardy and easy to grow, requiring minimal care, only full sun and good drainage to thrive.

Sedum are tough and easy to grow and will thrive and spread in droughty rockery edges in full sun. They will tolerate shade but prefer a position in full sun if they are to bloom well.
In summer, dense clusters of blooms smother the evergreen plants. In some varieties the flowering can be so dense that the leaves are completely hidden. If started early, it forms a nice dense ground cover the very first season. If the weather is favourable, they will flower within six months. If left, the sedum will self-seed in August or September.

Sedums are suitable for use in alpine gardens, troughs and other containers and successfully complement other rock-garden plants. Planted containers with other succulents they make wonderful components for miniature or fairy gardens.
Sedum make unusual and often showy ground covers and are successfully used as alternatives to lawns and green roofs. 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.They are also wonderful components for vertical walls. Sedum strut their stuff where many other plants dare not venture!

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

We would only recommend sowing directly for very small, sheltered areas. Generally you will get much better results if started in pots or trays and then planted out as plugs.

Prepare a fine weed free free-draining bed. Mixing seed with fine sand will aid even distribution. For green roofs using 1 gram of seed per square metre is advisable. 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. 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 cells or 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.

Cultivation:
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 fertilisation 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.

Plant Uses:
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.

Origin:
There are over 500 species of sedum, which include annuals, evergreen and deciduous perennials, sub-shrubs and shrubs, they are found mainly in the temperate parts of the northern hemisphere.

Nomenclature:
The 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.