Shrubby Hypericum - starting with H. frondosum

Submitted by Mark McD on Sun, 03/20/2011 - 21:54

I was initiated into the wonderful world or native Hypericum species, many being rather ornamental small shrubby plants, some with attractive peeling back, by George Newman of Bedford, New Hampshire. These are first class shrubs that are somewhat neglected in horticulture, but should be grown more often. One of the very best is H. frondosum, and Eastern/Southeastern USA species, often seen in the cultivar 'Sunburst':

It is one of those great all-around plants, a manageable small-medium sized shrub, super hardy in spite of its southerly range, with attractive blue-green leaves all summer, and a profusion of large yellow starburst flowers in summer, and wonderful fall foliar color, and interesting twiggy branching and persistent seed pods in winter.

I'll start by showing the winter appearance and late winter/early spring growth. This plant has been a feature of my "foundation planting" for almost 10 years, it is about 30" tall (75 cm) by about 4-1/2' (135 cm) wide... it could be pruned to be smaller. I leave the seed pods on, as they add some winter interest.

This shrub is the earliest shrub to leaf out here, in late winter each year, but doing so in such a subtle way that it is easy to miss this feature. From afar, the shrub looks completely deciduously dormant, but upon close inspection, it not only has new growth buds but has leafed out with linear scale-like leaves... always a surprise. But it is not until much later in the season, when the leaves actually expand, that the shrub begins to appear to be reawakening.


Submitted by Hoy on Tue, 03/22/2011 - 15:07

I do grow a few Hypericums but not this one! Seems to be a stout shrub. Maybe I should try it at my summerhouse? - do you know if it is livestock-proof, Mark ;D
But I mean it, I am looking for summer-flowering shrubs which tolerate summer dryness.

Submitted by Mark McD on Thu, 03/24/2011 - 06:14

In the summer months, Hypericum frondosum (golden St. John's wort; but aren't they all?) is a true asset in the garden, making am intricately branched small shrub wider than tall, sheathed in oblong refreshingly blue-green leaves.  

For a long period in mid summer; July-August, come a profusion of large golden powder puffs, bumble bees nearly glued to the flowers with their attraction. Older spent flowers age to a bronzy orange color.  Buds are produced in long succession such that 8-10 weeks of bloom can be had.  Every year when I enjoy this native shrub through all its seasons, I wonder why it is not more commonly encountered in gardens.

Submitted by Mark McD on Thu, 03/24/2011 - 06:29

I love multifaceted plants, those that offer great appeal throughout the year.  Hypericum frondosum does not let us down in the fall season, as it proceeds into a slow burn of hot foliar color.  Fall color is variable, particularly true of seedlings which show such variation that one could select cultivars for fall color alone.  In most cases the late-senescent foliage turns yellow, slowly taking on shades of orange, salmon, red, or maroon.

The photo on the left shows my main bush in early color change, with light yellow to reddish tones; the colors will intensify.  In the center is a seedling plant with leaves in maroon to bright red.  And the photo on the right shows a mixed grouping of 8-10 seedlings growing together, taking on various colors.  By the way, I should mention that H. frondosum seeds around mildly, and never becomes a problem.  It takes some number of years for seedlings to attain mid-shrub size, so it is easy to remove the few seedlings that do show up, if they're unwanted.