Sedum height ranges from a flat mat 2 to 3 cm high to an upright clump approaching a metre. The genus has no single answer; the four growth forms have four different height ranges.
Part of the Complete Sedum Guide.
Heights by growth form
| Growth form | Vegetative height | In flower | Typical species |
|---|---|---|---|
| Mat-forming creepers | 2 to 8 cm | 5 to 15 cm | S. acre, S. album, S. spurium, S. rupestre, S. sexangulare, S. dasyphyllum, S. lineare, S. ternatum |
| Upright herbaceous (Hylotelephium) | 20 to 70 cm | 30 to 80 cm | H. telephium, H. spectabile, 'Autumn Joy', 'Matrona', 'Purple Emperor' |
| Compact Hylotelephium hybrids | 15 to 30 cm | 20 to 35 cm | SunSparkler series ('Dazzleberry', 'Lime Zinger'), Rock 'N Grow series |
| Pendant trailers | Stems 30 to 100 cm long, hanging | Same | S. morganianum, S. burrito |
| Dwarf rosettes and stem-succulents | 10 to 30 cm | 15 to 35 cm | S. nussbaumerianum, S. adolphi, S. rubrotinctum, S. palmeri |
The flowering height is often 50 to 100 per cent more than the vegetative height because the inflorescence lifts clear of the foliage on a scape or terminal stem.
Specific examples
- Sedum acre — vegetative mat 2 to 5 cm, flowers on 5 to 8 cm scapes.
- Sedum album 'Coral Carpet' — vegetative 3 to 5 cm, flowers to 10 cm.
- Sedum spurium 'Dragon's Blood' — vegetative 8 to 10 cm, flowers to 15 cm.
- Sedum rupestre 'Angelina' — vegetative 8 to 12 cm, flowers to 20 cm.
- Sedum kamtschaticum — vegetative 10 to 15 cm, flowers to 25 cm.
- Hylotelephium telephium 'Autumn Joy' — vegetative 40 to 50 cm, flowers to 60 cm.
- Hylotelephium 'Matrona' — vegetative 50 to 60 cm, flowers to 70 cm.
- Hylotelephium 'Purple Emperor' — 35 to 45 cm.
- Sedum SunSparkler 'Dazzleberry' — 20 cm in flower.
- Sedum SunSparkler 'Blue Elf' — 15 cm, the smallest Hylotelephium hybrid in the trade.
- Sedum morganianum — stems pendant, 60 to 100 cm long from a hanging basket.
- Sedum rubrotinctum — stems sprawling, rarely above 20 cm tall in a pot.
- Sedum nussbaumerianum — 15 to 25 cm.
What affects actual height
Four factors move a plant within its species range:
- Light. Low light produces etiolated stems and exaggerated height, at the cost of colour and structure. A healthy plant hits the middle of its published range; a floppy tall plant is usually light-starved rather than genetically vigorous.
- Soil nutrition. Rich beds produce taller floppier growth in the Hylotelephium group. Lean soil keeps them compact.
- Water. Drought-stressed plants are slightly shorter.
- Cultivar genetics. Two plants labelled Hylotelephium telephium can differ by 30 cm depending on which cultivar they are. Always read the specific label.
When your sedum is shorter or taller than expected
If a Hylotelephium comes up under its published height, check light first; it may be in too much shade. If it is dramatically taller and flopping, the bed is too rich or too shady; the Chelsea chop (cutting back by a third in late May or early June) restores compact form within a season.
A mat-forming creeper that is suddenly tall is etiolated. It is reaching for light. Move it to full sun or take cuttings from the healthy portion and restart.