Verbascum densiflorum aka Mullein

Verbascum densiflorum is known as dense-flowered mullein. It belongs to the Scrophulariaceae family. Kew places its native range from Europe to the Caucasus. It grows in temperate climates and is not native to Britain or Ireland. In the wild, it occupies dry, sunny ground. Sites include waste ground and railway banks. It grows as a biennial or a short-lived perennial.

The plant forms a rosette before sending up upright, branching flower spikes. Some leaves remain through winter. Dense grey-yellow hairs cover the plant. The basal leaves have wavy edges. They can reach about 1.5 feet (0.45 metres) long. RHS gives a garden height of 5–8.2 feet (1.5–2.5 metres). Its spread reaches 1.6–3.3 feet (0.5–1 metre). The same account describes flower spikes reaching 5.9 feet (1.8 metres). Many flowers crowd these tall stems. Most are yellow, though white flowers also occur. Each can span about 0.16 feet (0.05 metres).

Give this mullein full sun and soil that drains well. RHS recommends poor, alkaline ground, including chalk and loam. Rich soil makes plants grow larger and may leave stems needing support. The plant tolerates drought and suits a sunny, exposed site. RHS rates its hardiness H6, covering winter lows near −20 to −15°C. Plants for a Future lists USDA zones 4–8. Plants reach their full size within one or two years.

Its upright form suits flower beds and informal cottage gardens. RHS also suggests gravel gardens and wildlife plantings. Remove flower spikes once their blooms fade. Sow seeds in containers within a cold frame during spring or early summer. Winter root cuttings offer another way to raise plants. Watch for mullein moth caterpillars and figwort weevils. Powdery mildew can also affect the plant. Plants for a Future does not flag it as weedy.

Plants for a Future records no known edible uses. It also lists no known hazards, but that does not establish food safety. The source records traditional medicinal uses for the leaves and flowers. These include preparations for coughs and other breathing complaints. It also describes flower-infused oil for ear and skin complaints. These records describe past uses, not proof of safe or effective treatment.