I’m surprised that Japanese Hydrangea Vine, Schizophragma hydrangeoides, isn’t planted more often. You can easily see the similarities to Hydrangea anomala petiolaris, the common climbing Hydrangea, but in my opinion it is a much prettier plant, and becomes established more quickly. It grows well in sun or quite a bit of shade and is hardy in zones 5-9.
Schizophragma hydrangeoides differs from Climbing Hydrangea in it’s growth habit and its blossoms differ slightly as well. Schizophragma grows rather flat against it’s climbing surface, attaching by aerial roots, as opposed to Climbing Hydrangea which sends out protruding branches. It is quite handsome climbing up limbed tall trees, as well as trained along a tall wall, reaching 20-30′ with time. In late June and July, 8-10″ flattened corymbs of tiny fragrant white fertile flowers ringed with showy heart shaped sepals appear, and age wonderfully through the season. (If you study a Climbing Hydrangea blossom, the sterile flowers are actually composed of 4 sepals.) There are several good cultivars to choose from: Schizophragma hydrangeoides ‘Roseum’ has lovely rose flushed sepals, and Schizophragma hydrangeoides ‘Moonlight’ has beautiful blue green ovate leaves with a silverly overlay, and the same large white flowers. Fall foliage on all forms takes on various hues of red, and in warmer climates, sometimes yellow tones.
Here on High Hill Road, much of the winter is spent searching for sources of the most promising new plants available in the horticultural market. We’re always optimistic, but we hold all newcomers to the standards set by great plants introduced in the past. Clematis macropetala ‘Lagoon’ introduced in 1958 by George Jackman and Son, has been on the market 52 years. Wow! This is comparable to the career of BB King and just as blue, but “the thrill is not gone”.
We planted Clematis m. ‘Lagoon’ at the base of a mop-headed silver leaved Capulin Cherry, Prunus salicifolia. That “bad-hair-day” cherry’s branches bowed down and insisted on giving ‘Lagoon’ a ride. As early as April, this vigorous clematis beguiles nursery visitors with blue blossoms as it adorns the branches of its silvery companion. “What is that blue flowering tree out near the parking area?” we are asked. You won’t need a tree to enjoy this 6 to 10′ vine, as it would do equally well climbing a trellis or arbor.
Clematis macropetala ‘Lagoon?’ needs little pruning. If it does get too rambunctious where it is planted, it can be pruned back in late June or July, after it has finished flowering, since it blooms early on old wood. Clematis like a slightly alkaline soil, so scratching in a handful of dolomitic limestone will keep it happy if your soils tend to be acidic. It is very hardy, growing well in USDA hardiness zones 3-8.