937 Hypericum calycinumCommon Names: Aaron's beard, creeping St. John's wort, Rose of Sharon, goldflower Family: Hypericaceae (St. John's wort Family)
Aaron's beard is semi-evergreen shrublet that gets only about 1 ft (0.3 m) tall, but it spreads vigorously by branching underground stems (called runners or stolons), and quickly covers quite a large area. The leaves are arranged in pairs, opposite each other on the stems. They are 2-4 in (5.1-10.2 cm) long and elliptic to oval in shape, dark green above (yellowish green in shade grown plants), and paler, glaucus green below with conspicuous net veins. The flowers are bright yellow, 2-4 in (5.1-10.2 cm) across and borne singly or in clusters of two or three throughout the summer and fall. They have five spreading petals and a dense tuft of protruding yellow stamens that looks like an old fashioned shaving brush. At the peak of flowering, the pollen bearing tips of the stamens (the anthers) are red, as though the brush had been dipped in rouge.
Hypericum 'Hidcote', one of the most popular St. John's worts, is believed to have resulted from the hybridization of H. calycinum and H. X cyathiflorum, itself a hybrid between two other European species. 'Hidcote' is a very showy shrub to 4 ft (25.4 m) tall, that produces an abundance of golden yellow flowers over a prolonged blooming season.
Hypericum calycinum is native to a region that stretches from Turkey to Bulgaria.
CultureAaron's beard thrives in poor, sandy soils. Mow it to the ground every year or two in winter or early spring to rejuvenate and induce new growth. Light: Aaron's beard does well in full sun to partial shade, and tolerates almost complete shade. The more sun it gets, however, the more it blooms. Plants in quite shady situations flower very little. Moisture: Although Aaron's beard can survive droughts, it does best with regular watering. Hardiness: USDA Zones 5 - 9. Some authorities give the hardiness zones as only 5-7. Aaron's beard suffers in hot, dry climates, and seems to do best in cooler, wetter areas. In the southern US, it stays evergreen through the winter, but blooms only sporadically. Aaron's beard is killed back to the roots by severe cold, but it returns in spring and blooms on new growth. Propagation: Start new plants from rooted underground stems, or from softwood cuttings.
Aaron's beard makes a great groundcover because it tolerates poor, dry soils, thrives in the shade, even over tree roots, and spreads fast. As a ground cover it has few peers. Use it to control erosion on slopes, or to cover that bare ground under the big oak tree.
Aaron's beard is one of very few effective groundcovers for dry, shady areas. And, it covers fast! There are more than 400 species in the St. John's wort genus, Hypericum, including many handsome shrubs native to the US, as well as the popular antidepressant herb from Europe, perforate St. John's wort (H. perforata), usually called just, "St. John's wort." Dozens of hypericums are native to the America's - one that is native to the southeastern United States, cedarglade (Hypericum frondosum) makes a handsome addition to landscapes and gardens.
Formerly classified within the family Guttiferae, the genus is placed in the family Clusiaceae by some authors, and in the Hypericaceae by others. Take your pick.
Aaron's beard spreads exuberantly, and under ideal growing conditions can become invasive and difficult to get rid of.
Steve Christman 12/31/01; updated 5/29/04, 6/9/04, 6/11/06