By Eric Barrett
Ohio State University Extension
For gardeners in Northeast Ohio, you either love hydrangeas or are frustrated by them. The frustrating part is planting one that results in no blooms the next year. This is because most gardeners do not realize all of the different species of hydrangeas and the multitude of cultivars that will grow beautifully in our area.
Most gardeners try to plant the big-leaf hydrangeas (hydrangea macrophylla). These are the big blue and pink flowering hydrangeas, also called florist hydrangeas. Many cultivars of bigleaf hydrangeas perform the best in zones south of the Mahoning Valley. They are mostly Zone 6 plants, which are not always as hardy as they could be when planted in our area. This is because these big-leaf hydrangeas bloom on old wood (last year’s growth) and many times the flower buds are injured during our winters. There are a few, like those in the Endless Summer family, which bloom on new wood and are much better repeat performers year after year. I suggest that nearly all bigleaf hydrangeas in our area need winter protection and care to be the best they can be.
As for hydrangeas in general, please note that the word hydrangea comes from two words and is translated as “water vessel.” Thus, they need to be located in a generally moist area. H. macrophylla varieties need the most water during the growing season. The soil pH should be between 5.0 and 7.5, depending on the variety. More acidic soils will reveal blue flowers on big-leaf hydrangea, more alkaline soils will reveal pink flowers. Somewhere in the middle will sometimes give a purple color.
Big-leaf hydrangeas are only the tip of the iceberg, so on to other varieties:
There are smooth hydrangea, oakleaf hydrangea, climbing hydrangeas and panicle hydrangeas. Each of these has a cultivar that will bloom beautifully here in our area. You can choose cultivars from each of these to have blooms from late May until the first frost in the fall. Here are some options to get started:
Smooth (bloom late May to August): Annabelle, Grandiflora, Invicibelle, Incrediball; Oakleaf (late May-September): Snow Queen, Alice, Snowflake (double); Big-leaf (late June-August): Endless Summer, Blushing Bride, Twist n Shout; Climbing (late June-July): anomala petiolaris, petiolaris “Firefly” (variegated); Panicle (late July-late October): Limelight and Little Lime, Bombshell, Great Star, Vanilla Strawberry.
Visit your local garden center to find these cultivars. For a copy of my chart explaining hydrangeas and details for growing in our area, see: http://go.osu.edu/hydrangeas.