Lamb's-Ears Also called betony (Stachys byzantina) Soft, silvery, woolly-looking, 4- to 6-inch leaves. Plant grows 12 to 18 inches tall and spreads by underground roots to make solid mat of cover. Flower spikes appear in summer with a lot of small, purplish blossoms. Generally grown for attractive leaves. Zone: 3-10 Light: sun Comments Hardy plant for hot, well-drained sunny areas. Space plants 12 to 18 inches apart. Needs little water. Grow from seed in spring or divisions of old plants in spring or fall. Remove old foliage in spring, give light feeding, then water.