Many people across the land are very unhappy right now. They're unhappy because their neighbor's hydrangeas are blooming and beautiful, their hydrangeas aren't, and they're afraid their shrubs' lack of cooperation is a sign of displeasure from the Big Guy.
If you're among those unhappy folks, relax. Believe me, if the Big Guy is mad at you, He has much more effective ways of demonstrating disapproval than taking it out on your hydrangeas. No, when hydrangeas don't bloom (and Grumpy is talking about all types of hydrangeas here), it's almost always due to one or more of the following reasons.
1. You pruned at the wrong time.
2. Your hydrangea isn't getting enough sun.
3. The flower buds were killed by a late winter freeze.
4. Your hydrangea doesn't like where it's growing.
5. Your hydrangea hasn't bloomed yet this year, but it will.
OK, now let's consider the main classes of popular hydrangeas (French, smooth, panicle, and oakleaf) and see how these 5 factors relate to each.
French or Bigleaf Hydrangea (Hydrangea macrophylla)
Let me get the name out of the way first. French hydrangeas come from Japan, not France. They're called French because many selections of this species were made and named in France. Due to their incredibly gaudy clusters of blue, purple, pink, or white flowers, they're the South's most popular kind. Here's what you need to know about blooming.
When They Bloom: Older, once-blooming selections like 'Nikko Blue' shown in the photo up top, bloom for 6 to 8 weeks, starting anywhere from late spring to midsummer, depending on your location and the selection. Newer, repeat-blooming types ('Endless Summer,' 'Forever & Ever,' 'Mini-Penny,' 'Twist n Shout,' 'Let's Dance') bloom repeatedly from spring until fall if they're happy, well-watered, and actively growing.
How Much Light: They bloom best if given sun in the morning and a little light shade in the afternoon, particularly during the hot summer. If you plant them in all-day shade, they won't bloom.
How Much Water: French hydrangeas are water hogs. Due to the huge amount of water transpired by their large leaves during hot weather, they wilt in a flash. You may have to water them as often as every other day in the South in summer if it doesn't rain. Repeat-bloomers will not repeat bloom if they go dry. Obviously, French hydrangeas are not good plants for low-rainfall areas.
What Kind of Soil: Rich, fertile, well-drained soil containing lots of organic matter to retain soil moisture. Acid soil (below pH 7) gives blue or purple flowers. Alkaline soil (above pH 7) gives pink or red blooms. White French hydrangeas stay white no matter the pH.
Where Not to Plant: Don't plant in poor, rocky, dry soil. Don't plant at the foot of big shade trees that compete with them for water and nutrients.
When to Prune: Once-blooming types flower from buds made last year. If these buds are killed by a late freeze or cut off by mistake, you don't get blooms. So prune the once-bloomers very lightly. Remove any dead growth in early spring. Shorten live branches only in summer immediately after the blooms fade. Repeat-bloomers, on the other hand, bloom on buds made last year and the current year. So even if a freeze killed last year's buds or you pruned the plant to the ground this spring, they'll still make new flowers this year. Just remove old blooms as they fade.
Smooth Hydrangea (Hydrangea arborescens)
Native to the South, smooth hydrangeas are less fussy, more cold-hardy, and easier to grow than the French. 'Annabelle' (below) is the most popular selection because of its huge white flowers. New pink-flowering types, such as 'Bella Anna' and 'Invincibelle Spirit,' are now heavily promoted.
When They Bloom: About the same time as the French. They'll bloom later if pruned in spring.
How Much Light: They take more sun than the French, but morning sun and light, afternoon shade in the South is still a good rule.
How Much Water: They prefer moist soil, but don't need as much water as the French.
What Kind of Soil: Fertile, well-drained; pH doesn't really matter, unless you live in a peat bog or lime pit.
Where Not to Plant: In full shade under big trees.
When to Prune: Smooth hydrangea blooms on new growth. Prune in winter or early spring. If you prune it back severely, you'll get massive flowers, but fewer of them. These big blooms may need support.
Panicle Hydrangea (Hydrangea paniculata)
Native to Japan and China, this is the toughest and most accommodating species described here and a great one for beginners. It tolerates heat, drought, full sun, and bitter cold. In fact, Grumpy considers its most popular selection, the treelike 'Pee Gee,' the crepe myrtle of the North. "Pee Gee' grows up to 20 feet tall, blooms in summer, and thrives all the way to Canada. 'Limelight' (below) is a more compact, bushy plant growing 5 to 8 feet tall with upright blooms that age from whitish-green to pink. I'm currently trialing a new dwarf, 'Bobo,' that tops out at 3 feet.
When They Bloom: Summer into early fall. The flowers of most turn from white to pink or rose as they age.
How Much Light: Full sun preferred.
How Much Water: Likes moist soil, but tolerates drought. Needs much less water than French.
What Kind of Soil: Well-drained.
Where Not to Plant: Shade (it won't bloom)
When to Prune: Blooms on new growth. Prune in winter or early spring.
Oakleaf Hydrangea (Hydrangea quercifolia)
Native to the Southeast, this is a unique hydrangea in several ways. It likes shade and will even bloom in the woods. It's the earliest to bloom of the species described here. Its oak-shaped leaves turn red, orange, yellow, and burgundy in fall. And it's far easier to grow than the French. My favorite selection is 'Snowflake,' named by nurseryman Eddie Aldridge of Birmingham, Alabama. As each flower cluster ages, stacks of new florets open atop the old ones. The new ones open white, while the old ones turn rose, giving a beautiful bicolored effect. 'Snowflake' grows 7 to 8 feet tall. 'Pee Wee' is dwarf and only grows 3 to 4 feet tall.
When They Bloom: Usually start in mid-to late spring and continue into early summer.
How Much Light: Dappled sun to shade.
How Much Water: Does well in moist soil, but tolerates drought very well.
What Kind of Soil: Well-drained, acid soil containing lots of organic matter.
Where Not to Plant: Full sun; near hot, paved surfaces; in alkaline soil (foliage turns yellow between the veins); in poorly drained, heavy soil.
When to Prune: Blooms on growth made the previous year. Seldom needs pruning, but if you must, do it in early summer.