This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A popular Caucasian perennial with dense masses of wrinkled, oblong-elliptic leaves covered with silvery-white woolly hairs. It is a very useful plant for borders, and produces its small purplish flowers in July on stems 12-18 in. high. These, however, should be suppressed to maintain the effective silvery appearance of the plants. Propagation is easily effected by division in autumn, and the young plants are sold in boxes in spring. About 80,000 can be grown to the acre, but one should not overstock such a free-growing hardy plant.