Hypericum Blue Velvet: drought tolerant shrub

I stumbled upon the use of Kalm’s St. Johnswort shrubs, a North American native, many years ago when looking for replacements for the common (yet solid-performing) Japanese spirea (Spiraea japonica) selections. In the Midwest, I would use the varieties ‘Ames’ and ‘Gemo’ fairly often for their mounded habit and yellow summer flowers. As low maintenance shrubs once established, they had much to offer and thrived in groupings, along the foundation and as accent plants. While that’s still the case, my world (as it relates to Hypericum kalmianum selections) was upended when I started growing the variety Blue Velvet.

In my observation, this selection displays the showiest blue in terms of foliage, is extremely floriferous and is a proven, top-notch performer. Admittedly, I almost exclusively use this selection, although the older varieties are still certainly solid in their performance. Paul Cappiello, executive director of Yew Dell Botanical Gardens (Crestwood, Kentucky), introduced this beauty and shared its origin story with me recently. Paul mentioned that he and John Wachter of Elite Growers, Inc. originally selected this notable, blue-leaved specimen from a batch of open-pollinated Hypericum kalmianum seedlings from well-known plantsman, Roy Klehm of Illinois. I see Blue Velvet listed as either a hybrid or Hypericum kalmianum in a wide range of literature and references.

Drought tolerant and disease-resistant shrub

This St. Johnswort prefers full sun but will tolerate part shade. Reaching 3 feet in height and a 4-foot width in time, the symmetrical form is a tidy dome that needs little attention and fills out to the ground. Average to dry soils are acceptable with a preferred soil pH between 6.0 and 7.5. Drought tolerant once established, sites with good drainage are vital (no standing water). The bright yellow flowers (2 to 3 inches in diameter) feature “fiber optic-like” center stamens and are intensely vivid against the blue foliage. This disease-resistant shrub flowers on new wood, so any trimming should be done right after the bloom period. A wide range of pollinators will be attracted to the flowers. The fruits are conical capsules that become red-tinged later in the season, but I see this contribution as tertiary after the foliage and flowers.