One of this plant’s country names is lamb’s tongue, but another name, rabbit’s ears, describes the soft, strokable quality of itsmore aptly. Primarily a foliage plant, the thick silver leaves of S. olympica make a thick, fast-growing, evergreen ground-cover, the rooting wher-ever they touch the soil. After mid-summer, woolly spikes about 18 inches (45 cm) tall, carrying tiny purple all the way up, rise from the mat of foliage. The plant is hardy, needs full sun (like most silver plants), and prefers light soil; a sticky soil does not suit it.
This is one of the most popular of all ground-cover plants, going particularly well with old roses or peonies in a border, or with purple-leaved shrubs; it is also useful as foliage in an all-white garden, or, more prosaically, as a cover for awkward banks. It suffers in heavy rain, when, said Mrs Margery Fish, ‘it looks like drowned rats’. It may also take a knock in a hard winter, but there are always enough scraps left to collect and replant in spring. There is a non-flowering variety called ‘Silver Carpet’, but it is liable to.
I suggest planting S. olympica sparsely to begin with, for economy’s sake, and letting it run about until it fills your spaces, when you can pull up the surplus.
Some of the most majestic mulleins are the Cotswold hybrids, tall, striking plants with branching spires crowded with saucer-shapedin late summer in yellow, pink, white, mauve or apricot. ‘Gainsborough’ is my favourite of the range because of its colour, which is a soft, pale, moonlight yellow. Grown in in a border it blends well with the deep blue of Anchusa or the steely blue of Echinops; there is a yellow and blue border at Clare College, Cambridge, where ‘Gainsborough’ mingles with delphiniums, , and achilleas to make a perpendicular planting as Gothic as King’s College Chapel in the background. At the opposite end of the scale, a single plant can make an eye-stopping punctuation mark in a sunny wild garden, perhaps rising from a sea of Lamium or other ground-cover. Growing to 4 feet (1.2 m) from its basic rosette of large grey leaves, it must be given a stake.
Verbascums need full sun and well-drained soil but not, I think, very poor soil. Aof wild common mullein once landed in my manure heap, and an enormous plant grew like Jack’s beanstalk to a height of 5 feet (1.5 m). ‘Gainsborough’ is sometimes listed as a perennial, but is best treated as a , for it is not long-lived. If grown in a group, plant 3 feet (90 cm) apart. Of the similar hybrids in other colours, ‘Pink Domino’, a pleasant rose-pink, is the best known.