Verbascums have a double value in the garden: their leaves are often covered in peculiar grey hairs, adding interest to the garden year round, and their stems of flowers pop up through other plants and often tower over the border.
The easiest to grow are biennials, and these include the wild V. thapsus (mullein) which has thickly felted leaves in flat rosettes and then tall, slender stems of bright yellow flowers. Verbascum bombyciferum is similar but better looking and brighter, and the flowering stems can reach 3m.
The perennial types are more popular because they do not leave a hole in the border after flowering and they are available in a wider range of flower colours including unusual pastel pinks and browns. The flower stems are packed with buds that open over many weeks, and most bloom from June to September.
Verbascum phoeniceum has pink and purple flowers above green leaves and is one of the most tolerant of clay soils and easy to grow from seed. They all cope with dry soils and grow best in an open, sunny spot. And they are, thankfully, usually untouched by rabbits, deer and snails.
Establishing your verbascum
Although they are hardy and tolerate low temperatures, verbascums dislike waterlogged soils. As a guide, the more hairy the leaves are the less they like moisture. If possible, plant them in spring so they have a whole season to get established before the winter wet.
Deadhead the larger flowered types to encourage new offsets at the base so they grow again the next year. The biennial types can be tricky to position because they form huge rosettes in the first year that look good at the front of the border and a huge stem the following year that you’d rather have at the back!
They are ideal plants for a gravel garden, a border behind a raised bed and on a rock garden where they have full sun and perfect drainage. If growing in pots use a loam-based compost and not multipurpose compost, which can hold too much water in winter.
The leaves of wild verbascums were used as wicks for oil lamps
Five striking verbascum colours to try
‘Pink Domino’ AGM
Spires of deep pink flowers all summer above grey leaves. Height: 1.2m (4ft)
Flowers in a pastel combination of yellow and butterscotch and long flowering. Height: 1.2m (4ft)
Enormous leaves in silvery white making rosettes 1m across in year one. Tall spires of yellow flowers the next. Height: 2.5m (8ft)
Striking blooms of palest pink with deep maroon centres on branched stems above greyish leaves. Height: 1.2m (4ft)
An unusual elegant, deep purple variety, flowering from mid to late summer. Height: 90cm (3ft)