At the end of the year gardeners are always on the lookout for plants that will help take the garden seamlessly from late summer into autumn. Grasses are one group, and for a splash of colour Dahlias, Rudbeckia and Helenium keep giving till the first frosts, but a rather unsung hero of the border is the sedate sedum. I don’t mean the increasingly used green roof type sedum, made up of small succulent-type sedum plants. I mean the herbaceous, taller sedums, plants which are commonly seen at the front of the border.
Boasting masses of star-shaped flowers in shades of white, pink and red they bloom from August to September. Popular with ornamental grasses, the extreme contrast in flower shape, the flat umbrellas of the sedum with the tall spires of the grasses make them good companions, the colours of the sedum with the grasses, both in their green coats and their dried winter cloaks enhance each other, adding to the textures and colours of the late season garden tapestry. Border sedums provide bulk and colour and are a magnet to bees and butterflies seeking nectar. Even when the flowers fade the seed heads continue to draw the eye. They are the perfect liaison plant, bridging the gap between tall perennials and the groundcovers.
Hugely impressive in any garden, Sedum telephium ‘Emperors Wave’ was introduced in 2005. It is ideal for adding a curious splash of colour to a garden even in winter. Growing to around 40cm (16in) tall, summer sees it produce some stunning purple-pink flower heads comprising a multitude of tiny individual blossoms standing on an erect stem, lending vibrancy along with it. Its succulent, blue-green foliage is shed by the time winter comes, but its seed heads remain in glorious shades of deep pink and purple.
Preferring well-drained soil, border sedums are happiest when situated in full sun or a lightly shaded spot, they will also thrive in 30cm (12in) containers filled with good quality compost. This is one tough little plant, hardy and drought resistant, their succulent leaves enable them to withstand the harshest of conditions, they will battle along without missing a beat
Sowing: February to April or August to October 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 directly into small pots is recommended. Fill pots with free-draining soil seed compost. Tap the pot to settle the compost and stand the pots in water, moisten thoroughly and drain. Mix the fine seeds with fine sand to aid even distribution. 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 plastic lid and place in a warm place. Care should be taken to prevent the pots drying out from below, keep the 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. 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 9cm pot or about 3 to 5 plants into an 11cm 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. 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.
Looking after sedums in the ground is easy. If planting this autumn, enjoy the flowers then allow the seed heads to remain into winter. Clear away foliage when it dies back and snip off seed heads when they eventually collapse. New growth will appear from the crown of plants in early spring.
The only point to watch is that some varieties of the taller sedums can be a bit floppy and lax in habit. This can be a problem if they are grown in too much shade, or rich soil, but this can be very easily overcome by pinching out the plants to make them bush or by Chelsea chopping them in late May or early June to produce bushier plants that flower a little later. Cut top growth by around 10cms (4in), this stops the floppy growth and makes a better behaved plant.
After three or four years rejuvenate overgrown plants by dividing in spring, prise from the ground with a spade, split into smaller pieces and replant.
Sedums are generally trouble-free plants but the new foliage is vulnerable to slugs as the new plants appear above the soil in spring. Use organic slug pellets or take a trip out in the evening to remove them by hand.
Beds and borders, Containers, Cottage/Informal, Drought Tolerant, Gravel, Low Maintenance, Rock Gardens.
A major advantage of Sedums is that they are greatly attractive to bees, hover flies and butterflies, especially when they first start to flower and are full of nectar. It is not unusual to spot several butterflies, a mass of bees and hover flies on a single Sedum plant on a warm autumn day. Sedums are also known as the butterfly's friend as they are really a magnet to butterflies.
Sedum is very wide-ranging genus of about 400 species with a variety of flowering colours and times. Mainly heralding from mountainous regions the Northern Hemisphere, from Eastern Europe to Russia, China and Japan, Sedum belongs to the plant family Crassulaceae, which includes such other succulent genera as Kalanchoe and Sempervivum.
The name Sedum is derived from the Latin word sedo meaning 'to sit'. This, together with the common name of ‘stonecrop’ refers to the manner in which some species of this genus attach themselves to rocks and walls and stony ledges.
The specific epithet telephium, honours Telephus, King of Mysia and son of Hercules, who reportedly discovered the virtues of this plant.
In recent years, horticultural taxonomists have deemed it necessary to split up the genus Sedum. Some plants that used to be classified in this genus have now been assigned to closely related genera such as Hylotelephium and Rhodiola.
For instance, Sedum spectabile has been renamed Hylotelephium spectabile, and Sedum telephium has been renamed Hylotelephium telephium. It takes a while for name changes like these to be reflected in retail nursery catalogues. But be aware that eventually gardeners will have to grapple with them.
- Additional Information
Packet Size 10mg Average Seed Count 125 Seeds Family Crassulaceae Genus Sedum Species spurium Cultivar Border Sedum, Emperor's Waves Synonym Hylotelephium telephium Common Name Emperor's Stonecrop
Recently renamed Hylotelephium telephium
Other Common Names Tall Stonecrop, Tall Border Sedum Hardiness Hardy Perennial Flowers Distinctive purple-pink umbels Natural Flower Time August to September Foliage Succulent, blue-green, mostly dark stemed. Height 40cm (16in) Spacing 40cm (16in) Aspect Soil Average to well-drained soil Time to Sow February to April or August to October Germination 14 to 21 days at 18 to 22°C (65 to 72°F)