Yellowdicks
Helenium amarum · Asteraceae
The gardener's calendar
Ideal time to plant yellowdicks: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Asteraceae
- Type
- Annual or biennial herb
- Flowering
- July to October
- Adult height
- 30 to 90 cm
- Foliage
- Deciduous, finely divided
- Hardiness
- Low hardiness, warm and temperate climate
- Origin
- North America (southwestern United States)
- Exposure
- Full sun to partial shade
Care
Exposure
Plant Helenium amarum in full sun for generous and abundant flowering. It tolerates partial shade but flower production decreases. This plant loves warm, open locations protected from strong winds.
Watering
Water regularly during growth and flowering, keeping the soil moist but not waterlogged. Reduce watering in autumn as the plant tires. Avoid stagnant water which promotes root rot.
Soil
Prefer well-drained, light and fertile soil. This plant tolerates poor soils but appreciates a substrate enriched with organic matter. Proper drainage is essential to prevent fungal problems.
Fertilizing
Apply balanced fertilizer every 15 to 20 days during flowering to support flower production. Diluted organic or mineral fertilizer is sufficient. Avoid excess nitrogen which would promote foliage at the expense of flowers.
Pruning and Training
Pinch young plants at the 4-6 leaf stage to encourage branching and a bushy shape. Regularly remove spent flowers to extend flowering. At the end of the season, cut back the plant or let it disappear naturally if it's annual.
Diseases and Pests
Watch for powdery mildew in case of excessive humidity or poor air circulation. Aphids and spider mites may occasionally appear in warm conditions. Encourage air circulation and avoid overhead watering to minimize risks.
Did you know?
Helenium amarum, also called "bitterweed" or "sneezeweed," bears the latter name because its pollen and volatile compounds trigger sneezing in some people when it flowers in autumn. Native Americans traditionally used it for its properties, and it remains a wildflower prized by southern American gardeners for its spectacular late flowering.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- SunflowerHelianthus annuus
- YarrowAchillea millefolium
- Ox-eye daisyLeucanthemum vulgare
- SneezewortAchillea ptarmica
- Canadian goldenrodSolidago canadensis
- WormwoodArtemisia absinthium
Tips generated and checked by Viridia — adapt them to your local climate.