• Woolly betony or lamb's ear (Stachys byzantina) is a mat-forming herbaceous perennial grown by gardeners for its soft gray-green leaves and summertime purplish blossoms. The tongue-shaped leaves grow in rosettes about 8 to 12 inches long on upright stems about 18 inches in height shoot up in early to late summer to bear the nickel coin-sized flowers. Grow lamb's ear in a full sun garden location in a well-drained soil across U.S. Department of Agriculture plant hardiness zones 4 through 8.
  
  

Big Ears

• The lamb's ear cultivar Big Ears develops slightly larger leaves than the wild species form of lamb's ear. Each medium green leaf measures up to 10 inches long according to the "A-Z Encyclopedia of Garden Plants," with a soft felt of gray-white. The summertime flowers on the tall stems are pinkish-purple to violet, attracting bees. The Learn2Grow plant database notes that 'Big Ears' is also sold under the name Countesse Helene von Stein.
  
  

Primrose Heron

• Primrose Heron lamb's ear looks and grows exactly like the wild species except that rather than gray-green leaves, this cultivar produces light yellow-gray foliage. Allan Armitage, author of "Herbaceous Perennial Plants" notes that as the summer progresses, the yellow coloration tends to fade and the fuzzy leaves turn more traditional gray-green. Flower color on Primrose Heron is pink-purple.
  
  

Cotton Boll

• Also sold under the cultivar name Sheila McQueen, this variety tends to attain more compact tufts of leafy rosettes compared to other lamb's ear plants. Not as much silvery "wool" occurs on the leaves, but the distinguishing feature of Cotton Boll is that the flowers are modified and occur all along the upright flower stems, resembling little balls of cotton.
  
  

Silver Carpet

• Armitage calls cultivar Silver Carpet the "best for low-maintenance gardening" as it requires little attention and spreads rapidly into a mass of ground cover.The leaves on this variety are intensely hairy and thus look silvery white. Unlike other lamb's ear cultivars, Silver Carpet does not produce any flowers.
  
  

Margery Fish

• Selected by and named after renowned 20th century British cottage garden designer Margery Fish, this variety of of lamb's ear produces silvery soft leaves. "A-Z Encyclopedia of Garden Plants" states that the variety's summertime flowers look mauve rather than the typical purple.
  
  

Silky Fleece

• Cultivar Silky Fleece is a lower-growing selection of lamb's ear, producing tufted leaf rosettes 4 to 10 inches tall. The gray-green leaves make a fine-textured ground cover when compared to larger-sized lamb's ear cultivars. In summer it produces fuzzy upright stems with whorls of lavender purple blossoms.