The name Hylotelephium is not one that rolls confidently off everyone’s tongue. To many of us they’re better known as sedums, but ten years ago the step was taken to recognise the differences between the 28 species now included in Hylotelephium and the hundreds still in Sedum.
Native to Europe, Asia and North America, and usually growing in open, well-drained situations, hylotelephiums were split from sedums on account of their broad, flat leaves and their branched, flat-topped or slightly domed flowerheads.
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Their roots also tend to be tuberous and there are other small but important distinctions. Plants develop tight woody crowns from which surge mainly upright stems carrying rounded or egg-shaped, noticeably succulent greyish-green leaves, arranged in opposite pairs up the stem, and often toothed along the edges. In many, the leaves are tinted purple or are entirely purple.
Fact file: Hylotelephium
- What Classic late-summer and autumn-flowering succulent perennials. A genus of 28 species (although only three species – Hylotelephium spectabile, Hylotelephium telephium and Hylotelephium cauticola – are usually seen in gardens). All were once included in Sedum and are part of the stonecrop (Crassulaceae) family. Commonly known as ice plants.
- Season July to October for flowers; seedheads can last until Christmas.
- Size 30-90cm high and around 15-90cm wide.
- Conditions Best in full sun, in well-drained soil that is not rich.
- Origins Europe, Asia and North America.
- Hardiness Fully hardy across the British Isles, with an RHS hardiness rating of H5-H7, and suitable for gardens in USDA hardiness zones 3a to 10b.
*Holds an Award of Garden Merit from the Royal Horticultural Society. †Hardiness ratings given where available.
The new growth is striking from when the distinctive shoots first emerge in spring. Then, in summer, flat-
topped or domed flowerheads begin to develop, each made up of a large number of small, starry flowers. In many, one impressive domed flowerhead matures on each stem, while in others flowering side shoots break from the leaf joints lower down to create a more informal look. Some develop more lax growth.
Not only is the flower power invaluable, but their appeal is enhanced by their succulent foliage.
Hylotelephiums are essential perennials for the autumn garden. Their heads of starry pink, white or purple flowers are dependable late-season stalwarts, but don’t let their reliability detract from their genuine appeal. For not only is their flower power invaluable, but their desirability is further enhanced by their after-flowering russet tones, as well as the colour and shape of their spring foliage. They are also highly attractive to butterflies and other pollinators, and it’s not uncommon to see two dozen butterflies on one plant.
Not all, however, are dependable insect attractors. Hylotelephium x mottramianum ‘Herbstfreude’, which retains its russet flowerheads until well into autumn, may be popular with gardeners, but has
the least appeal to insects. Hylotelephium spectabile ‘Brilliant’, on the other hand, is brilliant for them. It is often confused with two other Hylotelephium spectabile cultivars: ‘Carmen’ and ‘Meteor’. In theory, they open in slightly different shades of pink, but soil fertility and soil moisture can influence flower colour, so accurate identification is tricky.
How to care for Hylotelephium
Hylotelephiums thrive in sunny sites. They will flower well in areas shaded from the side by a fence or wall, but not if shaded from overhead by trees.
Hylotelephiums are relatively unbothered by pests or diseases. Although aphids, slugs or vine weevil are sometimes troublesome, your favourite organic treatment will usually see them off. Diseases such as root rot or leaf spots are usually more prevalent in wet conditions or wet summers.
When to divide Hylotelephium
Divide clumps in spring. Split the clump into pieces and replant those with the strongest growth. Each piece should have at least one bud or shoot, plus a piece of the crown with roots attached. Although hylotelephiums can be left for many years without much attention, without regular dividing and replanting, the stems become more crowded and the congestion forces them to lean outwards when, unless well supported, autumn rains can batter them to the ground.
Giving plants a ‘Chelsea chop’ in late May creates lower, more self-supporting growth; although I’d suggest chopping a little earlier in the month.
When to plant Hylotelephium
Plant in spring, improving both heavy clay soil and well-drained sandy soil with organic matter. In many soils, the stems are self-supporting, but a wire mesh frame, or canes looped round with twine, will provide unobtrusive support if needed. Avoid planting in rich soils. Soil that is starved is also unsuitable but can easily be improved with the addition of organic matter. In rich soil, growth will tend to be soft and weak and may collapse outwards.
The appeal of these tough perennials continues to broaden as new introductions become available
How to grow Hylotelephium from cuttings
Growing hylotelephiums from leaf cuttings is surprisingly simple and reliable. Snip or even pull off individual leaves, preferably with a bud at the base, then insert upright in 10cm pots of loose seed compost. Don’t firm the compost as this may encourage rotting. I’ve also seen
5-10cm shoots snipped off at the crown in spring and pushed into pots of similar compost. Don’t cover cuttings with polythene as this may keep them too damp and encourage rotting. You can also root 10-15cm cuttings in jam jars half full of water – just be sure to pot them up before emerging roots exceed 1-2cm.
Avoid growing hylotelephiums from seed. The quality of the cultivars raised from seed is so much less impressive than that of the thoughtful selections raised from cuttings and divisions.
The best Hylotelephium varieties to grow
Hylotelephium 'Matrona'
Stout upright stems carry unusually large, silvery-grey foliage with purple flushes and topped with flat white heads that open to pale-pink flowers. Robust and deservedly popular. Height and spread: 60cm x 45cm. AGM*. RHS H7. USDA 3a-9b†.
Hylotelephium telephium ‘Xenox'
Maroon stems carry olive- green leaves that turn plummy, making a good combination with the heads of bicoloured pink-and-white florets. 45cm x 45cm. AGM. RHS H7, USDA 3a-9b.
Hylotelephium ‘Red Cauli’
Purple stems carry contrasting green leaves and green buds that open to deep red, making an impressive display. A fine selection from Graham Gough. 60cm x 90cm. AGM. RHS H7, USDA 4a-9b.
Hylotelephium 'José Aubergine'
Tight, compact growth features rich-purple leaves the colour of aubergines that show off the dark-pink flowers harmoniously in August and September. 35-40cm x 35-40cm. RHS H7, USDA 3a-9b.
Hylotelephium telephium ‘Purple Emperor’
Similar to ‘Munstead Red’, its leaves emerge grey but soon mature to wine-red. The two-tone pink flowers become darker pink, maturing to biscuit brown. 50cm x 60cm. AGM. RHS H7, USDA 3a-9b.
Hylotelephium x mottramianum ‘Herbstfreude'
Long known as Sedum ‘Autumn Joy’, this robust selection features grey-green leaves topped with broad, deep-pink flowerheads. 80-90cm x 80-90cm. AGM. RHS H7, USDA 3a-9b.
Hylotelephium ‘Munstead Red'
Grey-green foliage with red marginal tints late in the season, and loose heads of pink-and-purple florets that become red in autumn. 45cm x 60cm. RHS H7, USDA 3a-9b.
Hylotelephium 'Wildfire'
Neat, wine-red leaves are edged in paler tones and topped with clusters of vivid flowers. Exceptionally well-branched, it makes a lovely specimen. From the impressive SunSparkler Series. 20cm x 40cm.
RHS H7, USDA 4a-9b.
Hylotelephium 'Bertram Anderson'
Neat, rounded leaves emerge grey-green then become darker and richer as the season progresses. Domed heads in wine and rose. Short, but tends to flop. 20cm x 35cm. AGM. RHS H7, USDA 4a-9b.
Where to see and buy Hylotelephium
- Beth Chatto Plants & Gardens Clacton Road, Elmstead Market, Colchester, Essex CO7 7DB. Tel 01206 822007, bethchatto.co.uk
- Cotswold Garden Flowers Sands Lane, Badsey, Evesham, Worcestershire WR11 7EZ. Tel 01386 422829, cotswoldgardenflowers.co.uk
- Hardy’s Cottage Garden Plants Priory Lane Nursery, Freefolk Priors, Whitchurch, Hampshire RG28 7FA. Tel 01256 896533, hardysplants.co.uk
- Southwold Succulent Company Mail order only. Tel 07368 431650, southwoldsucculentco.co.uk