Dense-flowered verbascum
Verbascum densiflorum · Scrophulariaceae
The gardener's calendar
Ideal time to plant dense-flowered verbascum: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Dense-flowered Mullein
- Family
- Scrophulariaceae
- Type
- Biennial herbaceous plant
- Adult size
- 1.2 to 2 m in height
- Flowering
- June to September
- Foliage
- Deciduous, gray-green downy leaves
- Hardiness
- Very hardy, down to -20 °C
- Origin
- Central and Southern Europe
Care
Sunlight
Verbascum densiflorum requires a sunny location, with at least 6 hours of direct sunlight per day for abundant flowering. It tolerates dry, resource-poor sites. Avoid dense shade, which would reduce flower production.
Soil and planting
This plant prefers well-drained, light, and poor soil. It adapts well to chalky, rocky, or sandy terrain. Overly moist or overly fertilized soil may promote vegetation at the expense of flowering. No organic matter is necessary.
Watering
Once established, this mullein is very drought-resistant. Water regularly in the first year to encourage rooting. After that, limit watering except during prolonged dry spells. Excess water is more damaging than water deficiency.
Fertilizer
No fertilizer is essential. Poor soil is sufficient for this robust plant. Excess nitrogen would promote dense foliage at the expense of flowering and increase susceptibility to disease.
Pruning and maintenance
Remove spent flower heads as they fade to extend the flowering period. At the end of the season, cut the plant back to ground level if it becomes invasive. Leave some dried stems standing in autumn and winter for architectural interest and ecosystem support.
Diseases and pests
Verbascum densiflorum is very robust. Powdery mildew may occasionally occur in humid conditions: ensure good air circulation. Caterpillars may consume leaves without significantly harming the plant. Treatment is generally unnecessary.
Did you know?
Verbascum densiflorum was called 'St. Fiacre's herb' in traditional herbal medicine and was used in infusion for respiratory conditions. Its dense, bright yellow flower spikes remain spectacular for several months, making this humble plant a star of dry, wild gardens throughout Southern Europe for centuries.
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.
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Tips generated and checked by Viridia — adapt them to your local climate.