In temperate climates, ‘Annabelle’ smooth hydrangea (Hydrangea arborescens ‘Annabelle’) is among the most popular landscape shrubs. You simply can’t miss its big pompons of pure white flowers from midsummer through early fall. In my neighborhood alone, I’m sure at least one house out of five features this shrub. And it’s been around for quite a while. ‘Annabelle’ was first discovered in the town of Anna, Illinois (whence the name Annabelle) in 1960 and was first made available to gardeners starting in 1962.
Despite its popularity, ‘Annabelle’ is not without its flaws and the one that annoys gardeners the most is that its stems, rather thin, often flop over under the weight of the huge ball of sterile flowers. But there is now an easy solution to this problem: the brand-new cultivar ‘NCHA5’, sold under the trade name Invincibelle Wee White®.
It is essentially a dwarf ‘Annabelle’, about half its height! At only 1 to 2 ½ feet (30 to 70 cm) tall, compared to 3 to 5 feet (90 to 150 cm) for ‘Annabelle’, but with a pompon of flowers almost as large, its shorter stems are better able to stand upright, even under torrential summer rains. In addition, while ‘Annabelle’ normally only produces one crop of flowers, Invincibelle Wee White is an rebloomer, flowering on and on, thus extending the season of interest right through to the end of fall. Another difference: the flowers age to pink and green as they mature while those of ‘Annabelle’ go straight to green.
Because of its smaller size, Invincibelle Wee White is an excellent choice for borders and container gardens and is also useful in mass plantings. As with ‘Annabelle’, its winter effect is also interesting, although its flowers are dry by then, they still hold on to the plant. Like ‘Annabelle’, Invincibelle hydrangea Wee White also makes an excellent fresh or dried cut flower.
Easy to Grow
Invincibelle Wee White is as easy to cultivate as its parent.
Give this North American native full sun or partial shade and any relatively rich and well-drained soil. It can be pruned back by about one third in the spring just as new buds start to appear. This will stimulate maximum bloom.
It’s not a very greedy plant and will get along fine with no fertilizer unless your soil is extremely poor. If you want to fertilize it, do so lightly with an all-purpose one. Avoid fertilizers rich in nitrogen, as they tend to encourage foliage growth over flowering.
Finally, Invincibelle Wee White is extremely hardy, to zone 3, tolerating -40˚ F (-40˚ C) with aplomb.
No smooth hydrangea (H. arborescens) is fully resistant to the hydrangea leaf-tier, an insect that seals the leaves at the end of the stems together and can cause flowering to partially abort. But since Invincibelle Wee White is a rebloomer, you can simply cut off the offending stem tips and it will soon be back in flower. Since there is only one generation of leaf-tier a year, it won’t attack again.
Invincibelle Wee White received the prestigious Green Thumb Award from the Direct Gardening Association as one of the best new horticultural introductions of 2018.
Although new for 2018, Invincibelle Wee White is apparently already available throughout Canada and the United States. I assume it will reach Europe in a year or so.