Large group of shrubs and perennials bearing yellow flowers that resemble single roses with a prominent sunburst of stamens in center. Open, cup-shaped, five-petaled blooms range in color from creamy yellow to gold; flowers may be solitary or in clusters. Neat leaves vary in form and color. Plants are useful for summer flower color and fresh green foliage. Various kinds are used for mass plantings, ground covers, informal hedges, borders. Most types resist deer damage. Perform especially well in mild, moist areas.
H. beanii (H. patulum henryi). Evergreen shrub or perennial; more perennial-like in Upper South. Zones US, MS; USDA 6-7. From China. To 4 ft. tall and slightly wider, with light green, oblong leaves on graceful, willowy branches. Flowers brilliant golden yellow, 2 in. across, midsummer into fall. Good for low, untrimmed hedge, mass planting. Shabby in winter.
H. buckleyi. BLUE RIDGE ST. JOHNSWORT. Deciduous shrub. Zones US, MS, LS; USDA 6-8. Native to mountains from North Carolina to Georgia. Spreading plant to 1 ft. high; space plants 2 ft. apart for ground cover. Rich green leaves to 1 in. long, rounded at tip. Golden yellow flowers to 1 in. wide bloom in summer. 'Appalachian Sun' is compact at 10 in. high and 18 in. wide.
H. calycinum. AARON'S BEARD, CREEPING ST. JOHNSWORT. Evergreen to semievergreen shrub; tops often killed in cold winters but come back in spring. Zones US, MS, LS, CS; USDA 6-9. From Bulgaria, Turkey. To 1 ft. high, spreading by vigorous underground stems. Short-stalked leaves to 4 in. long are medium green in sun, yellow-green in shade. Bright yellow, 3-in.-wide flowers bloom all summer. A tough, dense ground cover that competes successfully with tree roots, takes poor soil. Fast growing; will control erosion on hillsides. May be invasive unless confined. Plant from flats or as rooted stems 112 ft. apart. Clip or mow tops every 2 or 3 years during dormant season.
H. frondosum. BLUELEAF ST. JOHNSWORT. Deciduous shrub; evergreen in mildest areas. Zones US, MS, LS; USDA 6-9. Native to southeastern U.S. Grows 13 ft. tall, with mounding form. Blue-green leaves set off clusters of 112-in., bright yellow flowers that bloom from midsummer to early autumn. 'Sunburst' forms a tight mound to 3 ft. tall and wide.
H. 'Hidcote' (H. patulum 'Hidcote'). Evergreen to semievergreen shrub. Zones US, MS, LS; USDA 6-8. To 4 ft. tall and 5 ft. wide. Leaves 23 in. long. Yellow flowers, 2123 in. wide, bloom all summer.
H. xmoserianum. GOLD FLOWER. Evergreen subshrub or perennial. Zones US, MS, LS; USDA 6-8. Mounding plant with arching, reddish stems; reaches 23 ft. tall and wide. Leaves are 2 in. long, with blue-green undersides. Blooms in summer and possibly into fall, with golden yellow, 212-in. flowers borne singly or in clusters of up to five. Cut back in early spring. 'Tricolor' has gray-green leaves edged in pink and white.
H. patulum 'Sungold'. Semievergreen shrub. Zones US, MS, LS; USDA 6-8. Selection of a species from China. Twiggy, rounded growth to 12 ft. tall, 23 ft. wide. Oval, pointed 2-in.-long leaves. Golden yellow, 2- to 3-in.-wide flowers bloom in summer. Sometimes sold as H. kouytchense.
H. prolificum. SHRUBBY ST. JOHNSWORT. Deciduous shrub. Zones US, MS, LS; USDA 6-8. Native from New Jersey to Georgia. Slow, dense grower to 14 ft. high and wide. Narrow, shiny, dark green leaves grow 13 in. long. Bears 1-in., yellow blossoms late spring to late summer. Attractive in masses.
H. reductum. ATLANTIC ST. JOHNSWORT. Evergreen shrub. Zones MS, LS, CS; USDA 7-9. Native to sandy, scrubby sites from North Carolina to Florida and Alabama. Forms a mat to 1112 ft. high, 24 ft. wide. Aromatic, needlelike green leaves turn bronzy in winter. Small (to 23-in.-wide) yellow flowers bloom in early summer. Once established, needs no supplemental watering.