Verbascum, mullein

Verbascums are reliable show stoppers, adding height, structure and a profusion of colour to summer borders.

Recommended varieties

New colourful varieties are being bred continually.

Verbascums are either deciduous perennials or biennials. Be warned: the biennial varieties self-seed copiously. If possible, leave seedlings where they appear naturally, because they're very drought-tolerant.

V. olympicum : the classic mullein and most familiar species among gardeners. This biennial bears 2m (6ft)-tall clusters of golden yellow flowers from mid-summer to August. Like all biennial varieties, it produces masses of seed. Left unchecked, this plant can quickly colonise parts of the garden.
V. bombyciferum : this evergreen, erect biennial produces upright stems of densely packed yellow flowers in late summer. Its rosettes of large leaves are heavily felted in soft, silver-grey hairs, making this plant stand out in bleak winter months.
Verbascum chaixii 'album': known as the nettle-leaved Mullein, this perennial is half the height of the larger biennials, but nevertheless striking. The rosettes of delicate-felted, semi-evergreen foliage provide interest in winter, while tall, upright spikes of single white are a gorgeous site in late summer.
Verbascum ‘Cotswold Queen’ : this is popular for its deeply veined leaves and branched stems of apricot flowers marked with a purple eye.
Verbascum ‘Gainsborough’ : a favourite variety, this plant bears tall stems of saucer-like, pale yellow flowers.
Verbascum ‘Helen Johnson’ : this is a lovely plant with cabbage-like rosettes of greyish foliage in winter, crowned with tall spikes of single pink flowers.

Growing tips

Site and soil preferences

All verbascums tolerate a wide range of soils, but a well-drained site and full sun is preferable. The plant has a tendency to grow too tall in rich soil; staking may be required.

Propagation

Plants can be propagated by seed in spring or late summer after flowering, or through root cuttings in winter.

Planting associations

Plant them at the back of a sunny border, next to other summer-flowering plants. Try them with Delphinium ‘Black Knight’ or Aconitum carmichaelii 'Barker's Variety' .

Problem solver

Verbascum suffers from catepillar damage. The caterpillar, which emerges in May and June, can destroy a plant in a day. Pick off the catepillars to avoid serious damage.