Easily grown in average, medium, well-drained soils in full sun to part shade. Prefers rich, sandy loams. Tolerant of some drought. Mulch roots in winter. Top growth is not reliably winter hardy throughout the St. Louis area where plants may suffer tip dieback or die entirely to the ground in harsh winters. When plants die to the ground in winter, the roots often survive and send up new shoots in spring. Flowers bloom on new wood, so winter damage will not adversely affect flowering.
Hypericum frondosum is a small, dense, upright, mounded deciduous shrub that is noted for its large showy golden yellow flowers and attractive blue-green foliage. It grows to 3-4’ tall and as wide. It is native from Kentucky to North Carolina south to Georgia, Alabama and Texas where it typically occurs in rocky hills, limestone glades and barrens. Features linear to oblanceolate blue green leaves (to 3” long) and mostly solitary bright yellow 5-petaled flowers (to 1.75” diameter) with dense bushy center stamens. Blooms in June and July. Flowers give way to reddish-brown narrow ovoid fruit capsules that ripen in September and persist well into winter. Attractive exfoliating reddish-brown to purplish bark develops on mature stems. Foliage is semi-evergreen to evergreen in the southern part of its growing range.
Genus name comes from the Greek words hyper meaning above and eikon meaning picture in reference to the practice of hanging flowers from this genus above images, pictures or windows.
Specific epithet means leafy.
'Sunburst’ is a popular cultivar that, in comparison to the species, features slightly larger flowers (to 2” diameter) on a more compact plant (to 3’ tall).
Wilt and root rot can be significant problems, particularly in hot and humid climates of the South. Susceptible to nematodes which can cause root rot. Leaf spot, mildew and rust are less threatening.
Hedge. Shrub border. Foundations. Effective when massed.