GARDENING Fans' love of hydrangeas blossoms, keeps growing

Hydrangeas offer versatility, colorfulness and are simple to grow.
By MEGAN SEXTON
KNIGHT RIDDER NEWSPAPERS
COLUMBIA, S.C. -- Hydrangeas, many gardeners know, can be addictive.
A mainstay of many summer gardens, they're old-fashioned but offer new varieties.
They're colorful, in shades from petal-soft pinks to brilliant blues. The blue is especially popular, because it's a hue not easily available in the garden.
They're versatile, working as shrubs in larger gardens, in patio containers or as cut flowers at the center of the kitchen table.
They're easy to grow, thriving in slightly acidic, well-drained soil and blossoming in the filtered sun under a high canopy of pine trees that dominate some landscapes.
And how many other plants allow you to change the color of the bloom by altering the soil?
"It's like iced tea and fried chicken," said garden designer John Long of Longscapes. "People just love hydrangeas."
Getting hooked
Gardener Pat Bynum caught the hydrangea bug six years ago after completing a Master Gardener course. She attended the Master Gardeners' spring symposium at Riverbanks Zoo and Gardens, where American Hydrangea Society founder Penny McHenry of Atlanta was a guest speaker.
"I was hooked," she said. "That was the real beginning of my passion to grow hydrangeas."
Since then, Bynum has filled her garden with more than 200 of the plants, which bloom from spring until frost.
The appeal? "They really make a statement. They just light up your whole yard," she said. "When you walk into a garden with hydrangeas, you just say, 'Wow.'"
Hydrangea primer
When most people think of hydrangeas, they usually picture Hydrangea macrophylla.
Also called bigleaf or French hydrangea, Hydrangea macrophylla has pink or blue flowers.
"Macrophylla" means "big leaf," referring to the large, bold leaves. Those types are divided into two shapes -- mopheads and lacecaps.
Mopheads have sterile flowers in solid masses. The flowers can get so heavy they cause the stem to bend.
The lacecaps have a center of fertile, relatively nonshowy flowers and an outer ring of showy, sterile flowers, which together form a pinwheel effect. The name "lacecaps" comes from the caps servant girls used to wear in Europe.
Other popular types
Oak leaf hydrangeas (Hydrangea quercifolia) are especially popular. They bloom in late spring through early summer, and their white flowers fill the landscape -- and are perfect for cutting and drying.
This plant grows to about 6 feet tall and as wide as 7 feet.
There are dozens of varieties, with "Snowflake" being one of the most common -- and popular.
Colors
Can I really change the colors of my hydrangeas?
Flower color is determined indirectly by the soil pH, which affects the availability of aluminum in the soil.
In acid soils, the flowers will be blue; in alkaline soils, the flowers will be pink.
A lower pH produces more intense shades of blue. Adding powder sulphur (4 to 8 ounces per square yard) to the soil of light blue hydrangeas will turn them a darker shade of blue.
Hydrangeas in the landscape
Hydrangeas have myriad uses in the landscape.
Bigleaf hydrangeas are effective as single plants, in groupings or in containers on the deck or patio.
Because the bloom is so showy, it is a dominant plant in the landscape.
"It's a focal point. It needs to be displayed in full view," Long said. "It does great from a distance, too."
He suggests using a single hydrangea or using several in a mass planting as a dominant element. You lose effect when you have five or six of the plants spotted around the landscape, he said.
Easy growers?
Hydrangeas like well-drained soil with plenty of organic matter or humus.
Most hydrangeas like morning sun and afternoon shade. Keep them away from hot, dry areas and places that get intense afternoon sun.
When to plant
Spring or fall is the best time to put them in the ground. Dig a large hole about 2 feet across and 1 foot deep.
Bigleaf hydrangea responds to several light applications of fertilizer during the growing season. A general-purpose fertilizer, such as 10-10-10 applied at a rate of 2 cups per 100 square feet is suggested.
Water soon after application to help dissolve the fertilizer and send it into the soil.