|Flowers of Hypericum kalmianum (left) and H. frondosum (right)|
Years ago the hybrid 'Hidcote' made a big splash in local gardening circles, but it soon became apparent that its wood was not particularly winter hardy, although plants badly cut back by the cold usually sprouted from the ground later.
The two shown here, Hypericum kalmianum and H. frondosum, are native to North America. H. kalmianum is native to the northern and eastern tier of states here in the US and adjacent Canada, and one need not be concerned about its cold hardiness in local gardens. Hypericum frondosum on the other hand, is a southerner, yet it seems to thrive in local gardens. Self-sown seedlings appear now and then. Of the hypericums I know and have grown, it's the favorite. It does not suffer winter die back, and its branches with peeling bark give it the appearance of a small tree.