CHARLESTON, W.Va. -- My friend Joanne, like many others in our area, has a hydrangea that's lovely -- if you like leaves with no blooms. There are a lot of things that can cause a hydrangea not to bloom, so I'll head over to her house to see which solution is right for her situation.
The right mix of light, nutrients and water, plus winter protection will produce abundant blooms in hydrangeas.
These deciduous woodland shrubs are native to Japan. They do well in Hardiness Zones 5 to 9. They prefer moist, well-drained soil but can develop yellow leaves, a symptom of chlorosis, in highly alkaline soils.
Typically, the plants range from 3 feet to 6 feet tall, but wind and cold temperatures can cause injury and hinder overall shrub size.
Plant these beauties along a large stand of trees -- bigleaf hydrangeas grow well in the shade in most areas of the United States; however, too much shade can result in great leaves and no flowers. The high shade created by deciduous trees or evergreens is perfect for bigleaf hydrangeas in our area.
Another problem can be too much fertilizer. A high-nitrogen fertilizer will result in beautiful leaves and few, if any, flowers. Bigleaf hydrangeas can tolerate very high levels of fertilizer without showing signs of fertilizer burn, so practice moderation. Too much water and too much dryness can also result in a lack of flowers.
If your hydrangea isn't flowering, you may be pruning it at the wrong time.
Mophead hydrangeas do not have to be pruned back -- ever -- unless they are very old. Only remove dead stems or dead blooms.
But if your hydrangea is getting much too large (or old), and you must prune it, use one of the following methods.
Mophead or lacecap pruning
For mophead or lacecap hydrangeas (these are the only type of hydrangeas that are usually blue or pink) or oakleaf hydrangeas (leaves shaped like large oak leaves, white blooms), prune these hydrangeas only in the summer before August (to be safe). Some experts believe these hydrangeas may be pruned even into August, but this might be risky -- the hydrangeas may already have set their bloom buds for the next year. These hydrangea types bloom on old wood (stems that have been on the plant since the summer before the current season).
This group of hydrangeas produces flower buds on hydrangea stems around August, September or October for the following summer's blooms. If those stems are removed (pruned) in the fall, winter or spring, the bloom buds will be removed, and there may be little or no bloom the following summer.
There is a small group of mophead hydrangea that will bloom no matter when they are pruned. ('Endless Summer' is this type of hydrangea). Your garden center can tell you when you purchase a hydrangea if it is in this special category called "everbloomers." But for the vast majority of hydrangeas, pruning after July will likely result in fewer blooms the next summer.
Some blue mopheads to try include: "All Summer Beauty" and "Nikko Blue," "Mathilda Gutges," violet-blue flowers; "Générale Vicomtesse de Vibraye" can be light blue or pink.
Pink cultivars include: "Glowing Embers" and "Masja." For white flowers, try "Madame Emile Mouillère."
Annabelle or PeeGee pruning