You can't beat hydrangeas for big, bold blooms

Hydrangeas produce big, gaudy flowers in sun or part shade, showy in the landscape and as cut flowers.

They brighten our summers with blooms of white, pink, purple, blue, green or some combination of hues.

Then the shades might deepen as the season progresses -- similar to the chemistry that turns leaves on trees.

For extra drama, some hydrangeas even bloom blue when they digest more aluminum from the soil, and pink with less.

More Coverage Links How to get the most Endless Summer blooms [03/15/08] How to change colors of hydrangea blooms [03/15/08]

No wonder the popularity of these shrubs -- beloved in America since colonial times -- continues to grow.

And as you might imagine, these days higher demand leads to more and more cultivars.

Breeders work to produce variegated or yellow leaves and more compact plants with the huge flowers we love, as some hydrangea shrubs grow rather large, and when or whether to prune is always a tricky issue.

Another goal is varieties that bloom on both new and old wood -- or at least on new wood.

That is aimed directly at us northerners.

The flower that most people think of when hydrangeas are mentioned is the snowball or mophead, a type of macrophylla. It blooms on old wood, which means it starts its buds in the fall, and a hard winter or late frost can kill them.

The plant would probably survive, but there might be a flowerless season, and hydrangeas are rarely cherished for their foliage.

Endless Summer from Bailey Nurseries led the way, producing buds on both new and old wood. That creates a sort of insurance policy. If a hard winter kills the old-wood buds, the new wood will grow more.

Now other companies are using Endless Summer to develop new varieties, which even competitors think will push out the traditional mopheads.

"People aren't going to want to grow hydrangeas that bloom just on old wood -- especially in the North," said Danielle Ernest, public relations and marketing assistant for Spring Meadow Nursery Inc. of Grand Haven, Mich.

Another type of macrophylla bears flowers called lace cap for their flat, disc-shaped appearance created by a combination of small and large florets.

Barbara Pierson, nursery manager for White Flower Farm, a mail-order company based in Connecticut, loves Blue Billow, a lace cap she grows in the shade.

"I like the lace cap understated flower better myself," she said. "They don't flop over, and mopheads tend to hang and look messy. The lace caps stay nice and compact and formal looking."

Plant people like Spring Meadow's Ernest urge Midwesterners to grow a hydrangea species called paniculata. These hardy shrubs -- which grow larger than the mopheads -- feature long, pointed flowers.

They set their blooms on new wood that comes up after winter is past. They also usually bloom later -- midsummer to fall. Spring Meadow recently introduced the showy Pinky Winky with two-toned white and pink flowers.

One of Benjamin Carroll's favorite hydrangeas is paniculata Tardiva, which grows on Evening Island at the Chicago Botanic Garden.

It can grow 8 to 10 feet tall, said Carroll, a senior horticulturist at the garden.

Paniculata are more drought tolerant than macrophylla.

Here are other hydrangeas that grow in our area.

bull; Arborescens, such as the white Annabelle, are hardy.

bull; Petiolaris is a climbing subspecies that is hardy.

Carroll likes the way its loose creamy white flowers soften a wall.

bull; Oak Leaf or quercifolia is the hydrangea you choose if you are looking for attractive foliage. These leaves even turn burgundy in the fall.

Pierson says Amethyst not only has great leaves, but its white flowers turn wine red. It also does not grow more than 6 feet tall.

Care tips

Here are some tips on caring for hydrangeas.

bull; The ideal place to plant most hydrangeas is where they get lots of morning sun and are protected from hot afternoon sun. However, some varieties produce flowers even in the shade.

bull; A slow-release fertilizer in the spring should be adequate.

bull; You don't want to overwater, and you don't want to risk root rot, but if your plants are in full sun they will need more water, especially in early years.

bull; Paniculata are more drought tolerant than macrophylla.

bull; With pruning, less is usually more, said Barbara Pierson, nursery manager for White Flower Farm in Connecticut. The worst method is to cut hydrangeas back in the fall because if the blooms grow on old wood, you just cut them off. You can always take off spent flowers and dead stems. Right after flowering is usually the safest time to prune if you must.

Clip off spent flowers on Endless Summer to encourage repeat blooming. Only the Annabelle should be cut back to the ground in the spring. Let petiolaris, the climbing hydrangea, grow. In places where you think it has gone too far or the look needs taming, cut it off.

bull; Winter cover -- important in the first few years and with less hardy varieties -- can include burlap, a fence made of evergreen boughs or mulch.