The nationally scarce striped lychnis (Shargacucullia lychnitis) moth depends entirely on this native wildflower as a food plant for its caterpillars. Dark mullein is a tall, elegant plant which grows on the chalky soils found around Winchester. These local conditions make gardens in the area perfectly suited to support both the plant and moth.

The striped lychnis moth used to be widespread across southern England but has declined in recent years due to habitat loss and loss of the dark mullein plant. Because its caterpillars rely solely on the dark mullein, the moth is especially vulnerable, yet incredibly simple for people to help.

Fiona Haynes, Reserves Officer at Hampshire & Isle of Wight Wildlife Trust, said: “The chalk soils around Winchester provide the ideal growing conditions which dark mullein prefers and, consequently, the striped lychnis moth. 

“Dark mullein is easy to grow from seed. For best results, start seeds in trays to grow plug plants before planting out.  A single plant in a sunny corner of a garden or community space can provide an important food source, while also supporting many other pollinators too. It’s a small action with a big impact.”

For the last three years, striped lychnis caterpillars have been recorded on restored habitat at a Hampshire & Isle of Wight Wildlife Trust nature reserve. With their vivid black‑and‑yellow stripes and bold presence on tall flower spikes, the caterpillars are among the most striking larvae in the British countryside. 

Striped lychnis moths typically lay their eggs on dark mullein in June, and these hatch into tiny striped caterpillars in July.  They spend their life as a caterpillar feeding on the flowers, before dropping into the soil to pupate, sometimes remaining underground for more than one winter.

Seeds and young plants are usually available from online wildflower seed suppliers and wildflower nurseries. Once established, dark mullein is low-maintenance, and tolerant of dry conditions. Its tall flower spikes of yellow flowers with pink stamens are attractive to a wide range of pollinators including bees, moths and hoverflies. 

Hampshire & Isle of Wight Wildlife Trust provides free gardening advice. To learn more about how to make space for nature in your garden, visit here.