Oenothera 'Crown Imperial'
evening primrose 'Crown Imperial'
'Crown Imperial' is an upright, clump-forming herbaceous perennial 40-50cm high with broad basal leaves and narrow, glossy, bright green stem leaves, green stems topped by clusters of flowers so that the plant looks like a small crown imperial fritillary, and flowers opening from red buds into large, bowl-shaped, vibrant yellow flowers from midsummer; the flowers are sterile so it does not self-seed
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Size
Ultimate height
0.1–0.5 metresTime to ultimate height
1–2 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | Green | ||
|---|---|---|---|---|
| Summer | Green | Yellow | Green | |
| Autumn | Green | Yellow | Green | |
| Winter |
Position
- Full sun
Aspect
West–facing or South–facing or East–facing
Exposure
ShelteredDrought resistance
Yes Hardiness
H5Botanical details
- Family
- Onagraceae
- Native to the UK
- No
- Foliage
- Deciduous
- Habit
- Columnar upright
- Genus
Oenothera can be annuals, biennials or perennials, upright or spreading in habit, with simple or lobed leaves and bowl-shaped, white, yellow or pink flowers over a long period in summer
- Name status
Accepted
How to grow
Cultivation
Grow in poor to moderately fertile, very well-drained soil, even stony soil, in full sun
Propagation
Propagate by internodal one-leaf softwood cuttings of unflowered shoots from late spring to midsummer, or by division in early spring
Suggested planting locations and garden types
- City and courtyard gardens
- Gravel garden
- Prairie planting
- Cottage and informal garden
- Cut flowers
- Flower borders and beds
Pruning
No pruning required
Pests
Diseases
May be susceptible to leaf spot, powdery mildews and downy mildews; root rot may be a problem in rich, wet, heavy soil. Generally disease-free
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