Helianthus 'Double Whammy' (d)
sunflower 'Double Whammy'
'Double Whammy' is a clump-forming perennial to around 90m tall with rich green, ovate leaves.Double golden-yellow flowers up to 15cm across are borne from summer into autumn and comprise a ring of elliptic ray florets surrounding a central mound of tubular disc florets
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Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drainedpH
Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Gold Yellow | Green | ||
| Autumn | Gold Yellow | Green | ||
| Winter |
Position
- Full sun
Aspect
East–facing or South–facing or West–facing
Exposure
Sheltered Hardiness
H5Botanical details
- Family
- Asteraceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Columnar upright
- Genus
Helianthus can be tall, erect annuals, tuberous or rhizomatous perennials, with coarse simple leaves and large daisy-like flower-heads
- Name status
Accepted
How to grow
Cultivation
Grow in a moderately fertile, humus-rich, moist but well-drained, neutral to alkaline soil in full sun. Needs a long hot summer to flower well. May need support
Propagation
Propagate by seed or division. Divide established clumps every 2-4 years to both increase plants and retain vigour. See sowing seeds indoors for further advice
Suggested planting locations and garden types
- Cottage and informal garden
- Prairie planting
- Wildlife gardens
- Patio and container plants
- Flower borders and beds
- Cut flowers
- Wall side borders
Pruning
Cut back after flowering
Pests
Diseases
May be susceptible to powdery mildews and Sclerotinia diseases
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