Sedum 'Purple Emperor'
Hylotelephium telephium 'Purple Emperor' · Crassulaceae
Dark, beetroot-purple leaves and stems all season, with dusky pink flower heads in late summer. One of the darkest foliage plants for full sun.
- Size
- 18 in tall, 18 in wide
- Zones
- 3 to 8
- Light
- Full sun
- Flowers
- Early August to mid September
- Pets
- Toxic to people
- Job in a bed
- Drift
A bed built around sedum 'Purple Emperor'
The planner designed this bed around sedum 'Purple Emperor' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why sedum 'Purple Emperor' stands where it does.
The plants
- 1 Sedum 'Purple Emperor' × 3, pink
- 2 Winter heath × 7, white
- 3 Bloody cranesbill 'Max Frei' × 3, pink
- 4 Brown-eyed Susan × 5, yellow
- 5 False sunflower 'Summer Sun' × 3, yellow
- 6 Silver sage × 1, silver leaves
- 7 Ornamental onion 'Purple Sensation' × 4, purple
- 8 Grape hyacinth × 12, blue
Why this plant
- The only flat plates. The others are bells, open bowls, daisies and others. Shape reads at a distance, where colours blur.
- A classic partner for silver sage. Both are on this plan. A pairing gardeners have proved outranks a general rule.
Why here
- In the middle. At 18 in it is the step between winter heath (10 in) in front and false sunflower 'Summer Sun' (3½ ft) behind: each is seen over the one before.
- A step in the back row. Next to brown-eyed Susan (4 ft), ornamental onion 'Purple Sensation' (2½ ft) and false sunflower 'Summer Sun' (3½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for 7 weeks. From early August to mid September.
- Part of the bed's peak. With bloody cranesbill 'Max Frei', brown-eyed Susan and false sunflower 'Summer Sun' in early August: 4 kinds at once. No week has more.
Planned as an English border: 4 of the 5 groups (80%) are drifts, longer along the bed than they are deep. The scheme leans cool (pink, purple and blue) and uses yellow for warmth, with white to calm things between them. The flowering is at its height from early August, with 4 kinds out together.
The planner's own design check: 11 Excellent, 6 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where sedum 'Purple Emperor' goes in a border
At 18 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
Dark purple leaves need a pale partner or they disappear: silver artemisia, blue fescue or lamb's ear makes them stand out. It stays more compact than 'Autumn Joy'.
- Dark foliage for sunny beds
- Contrast with silver and blue leaves
- Late-summer flowers
What to plant with sedum 'Purple Emperor'
Plants recorded as good partners for it, and what each pairing does:
- Lamb's ear: its silver leaves are a setting for the flowers, before and after; happy in the same dry soil.
- Blue fescue: its blue-green leaves are a setting for the flowers, before and after; fine leaves against its bold ones; low enough (10 in) to stand in front of it.
- Silver mound artemisia: its silver leaves are a setting for the flowers, before and after; fine leaves against its bold ones; happy in the same dry soil.
Questions about sedum 'Purple Emperor'
Does sedum 'Purple Emperor' need sun or shade?
Sedum 'Purple Emperor' grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does sedum 'Purple Emperor' grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does sedum 'Purple Emperor' flower in my zone?
In zone 5 it flowers early August to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Early August to mid September |
|---|---|
| Zone 4 | Early August to mid September |
| Zone 5 | Early August to mid September |
| Zone 6 | Early August to mid September |
| Zone 7 | Late July to mid September |
| Zone 8 | Late July to mid September |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should sedum 'Purple Emperor' be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 18 in (45 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many sedum 'Purple Emperor' plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used three in one group.
Is sedum 'Purple Emperor' poisonous?
Yes: mild toxicity to people. May cause mild stomach upset if eaten.
Rated from NC State Extension. Where references disagree, the more cautious rating is used.
Do deer eat sedum 'Purple Emperor'?
Mostly not. NC State lists it as resistant to rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after sedum 'Purple Emperor'?
Sedum 'Purple Emperor' is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall.
- Meadow saffron: from mid September to mid October, 6 in tall, to stand in front of it and cover its fading stems.
- Autumn crocus: from mid September to mid October, 5 in tall, to stand in front of it and cover its fading stems.
What does sedum 'Purple Emperor' look like in winter?
Sedum 'Purple Emperor' dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is sedum 'Purple Emperor' good for bees and butterflies?
Sedum 'Purple Emperor' is visited by pollinators, bees and butterflies.
More Hylotelephium
- October daphne Hylotelephium sieboldii
- Sedum 'Autumn Fire' Hylotelephium 'Autumn Fire'
- Sedum 'Autumn Joy' Hylotelephium 'Herbstfreude'
- Sedum 'Frosty Morn' Hylotelephium erythrostictum 'Frosty Morn'
- Sedum 'Lidakense' Hylotelephium cauticola 'Lidakense'
- Sedum 'Matrona' Hylotelephium 'Matrona'
- Sedum 'Vera Jameson' Hylotelephium 'Vera Jameson'
- Showy stonecrop 'Brilliant' Hylotelephium spectabile 'Brilliant'
- Showy stonecrop 'Neon' Hylotelephium spectabile 'Neon'
In these guides
- Rabbit-resistant plants
- Drought-tolerant perennials for full sun
- Plants for butterflies
- Plants for bees
- Plants with purple and burgundy leaves
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 18 in (45 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Early August to mid September; flat plates; pink
- Leaves
- Bold texture, herbaceous; purple
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Crassulaceae
- Comes from
- Europe, Russia, and North China
- Attracts
- Pollinators, bees, butterflies
- Stands up to
- Rabbits, drought
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.