Shrub Hypericum calycinum [Creeping St. John's Wort] Relatively trouble-free. Tolerates dry conditions well (even drier shade). Generally, tops are killed back in severe winters near its limit of hardiness. Mowing to the ground each spring improves aesthetics of the following regrowth. Slow to leaf out in spring. Can be invasive via spreading stolons. Poisonous to animals.
Shrub Hypericum kalmianum 'Ames' [Ames Kalm St. John's Wort] Hypericum kalmianum 'Ames' is a compact, mounded deciduous shrub that produces attractive, interesting, bright yellow flowers in mid to late summer. 'Ames' is reported to have better winter hardiness than the straight species.
Shrub Hypericum kalmianum 'Gemo' [Gemo Kalm St. John's Wort] Hypericum kalmianum 'Gemo' is a compact, mounded deciduous shrub that produces a profusion of small, interesting, bright yellow flowers beginning late spring and continuing all the way into fall.
Shrub Hypericum kouytchense [Large-flowered St. John's Wort] The Large-flowered St. John's Wort is a mounded, semi-evergreen shrub with arching branches. Blooming generally begins in June and can last through September. The large, up to 2.5" diameter, bright yellow flowers are crowned by a dome of many long stamens. Some sources state that this species is synonymous with Hypericum 'Sungold'.
Shrub Indiana Native Hypericum prolificum [Shrubby St. John's Wort] Hypericum prolificum is a compact, rounded Indiana native shrub. The attractive bright yellow flowers, appearing in summer, are unique and crowned by a dome of many long stamens. This species can suffer in hot and humid environments, causing it to become prone to root rot and wilt.