Prayers Help Blooming Hydrangea

Hydrangea plants produce some of our most spectacular flowers - and some of our worst frustrations.

One question centers around blooming - how to get them to bloom year after year.

It helps to know which hydrangea is which.

Is it the big leaf - the large round flowered fellow we see most often - or a smooth hydrangea with flatter flowers growing on a low shrub? Or, is it one of the panicles - in particular, peegee, or oakleaf with huge, white flowers atop branches of oak-shaped foliage? Or, is it the vining or climbing hydrangea?

That’s the selection to choose from for this region. They’re all grown with little care, but they seem to bloom only if God wills it.

Bigleaf hydrangea (H. macrophylla) is probably the most popular. Its huge flowers are beautiful, fresh or dried. Problem: It’s marginal for our area, hardy down to Zone 6, and we’re in Zone 5.

The large round flower clusters appear in mid-summer, if we’re lucky. Because flower buds are set on last year’s wood, they are very susceptible to winter kill. In fact, big leaf hydrangea buds die if they are exposed to temperatures below 20 degrees. Winter protection is a must for this beauty. To help protect exposed buds, tie the plant together, wrapping it in burlap, and mound pine needles around it.

Prune the big leaf hydrangea right after it has finished flowering. If the flower buds and stalks were winter-killed, prune the plant to the ground, then give it time. The hardy root system will send up new shoots - and great expectations - for flowers next year.

An added note about the big leaf hydrangea: Its cultivars are divided into two blossom types - globes and lacecaps, with flower colors of white, pink, red or blue. The soil’s pH (acidic level) can change the color of a blue hydrangea to pink, or vice versa. The lower the pH, the bluer the flowers. To lower the pH, add 1/4 ounce aluminum sulfate per gallon of water and apply it to the plant. However, if you purchased a pink hydrangea, it will stay pink.

The smooth hydrangea (H. arborescens), native to the eastern and central U.S., is a low-growing shrub with rather flat flowers that open in mid-June. The flowers start out green, turn white and finally fade to brown.

Annabelle is touted as one of the best smooth hydrangeas. Its 12-inch diameter flowers make a dramatic display atop erect stems. Since the smooth hydrangea blooms on new wood, it can be pruned to the ground in late winter.

Panicle hydrangea (H. paniculata) can actually be pruned as a tree. This huge plant can easily reach 15 feet in height. Its flowers are large white pyramid-shaped clusters. If the plant is pruned to a half-dozen primary shoots, the flowers will reach 18 inches in length. Praecox and peegee are hardy specimens of this group.

Panicle flowers develop on this year’s long stems. If the stems are cut close to the main stem, usually two large flowers will develop. If the stems are cut in half, three or more flowers will develop.

Oakleaf hydrangea (H. quercifolia) is one of my all-time favorites. Not only does it have large white panicle florets that change to a bluish pink, but the leaves are also extraordinary. They resemble dark, glossy-green oak leaves which turn deep burgundy in the fall. Even the peeling bark adds a bit of winter interest.

Young plants need to be protected during winter months. Since they set their flower buds on old wood, the buds are easily destroyed by harsh winters.

Climbing Hydrangea (H. anomala subsp.petiolaris) is one of the most beautiful vines around. It’s a slow starter, but once it gets going, it is spectacular. The positioning of its dark glossy leaves and white blossoms give the vine a three-dimensional appearance. Little pruning, if any, is necessary.

All hydrangea like rich, well-drained, slightly acidic, moist soil. Most like sun, except the oakleaf and smooth hydrangeas which prefer some shade. Because our soils are more neutral than the acidic, fertilize hydrangeas with an acid-based fertilizer and a chelated iron.

For blossoming? Prune them correctly, protect them during the winter - and pray.

, DataTimes MEMO: Phyllis Stephens is a horticultural consultant and landscape designer in Spokane.

The following fields overflowed: CREDIT = Phyllis Stephens The Spokesman-Review