Hydrangeas in the Landscape - A Guide to Growing Summer's Most Breathtaking Bloomer

Hydrangeas in the Landscape
A Guide to Growing Summer's Most Breathtaking Bloomer

Story by Jackie Zilliox, Photography by Robert Tinari

Hydrangeas are flowering shrubs that are easy to grow and provide beauty with their long-lasting, rich, and colorful bloom. Experts can't agree on how many species there are at this time, however seven main classifications are recognized.

Anomala is a Climbing Hydrangea that can grow to 80 feet in height. Since hydrangea are deciduous the stems are just as interesting as the flowers with exfoliating cinnamon colored bark.

"These plants need adequate supports," Ann Waring, Master Gardener of St. Mary's County tells me, "and Japanese beetles are a pest for them."

Arborescens, known as Smooth Hydrangea, have weak stems and blooms on new growth. They grow five feet tall and wide. Their white flowers age to a light green color. They can grow in sun or shade and like moist soil. A new introduction to look for is 'bounty'.

Most likely grandma's type of hydrangea was the Macrophylla, or Bigleaf. In that species the flower has a full round "mophead." A popular group of the species known as "lacecap" has flat centers made up of tight fertile flowers with a single ring of sterile flowers encircling it.

"My favorite lacecap is 'Tokyo Delight'," Ann adds. "It is a pale off white that turns a deep rosy burgundy as it matures. They lend themselves nicely to drying."

Two of the newest macrophylla introductions are 'Endless Summer,' which has pink or blue flowers and blooms continuously on new wood. 'Lady in Red' has red stems and green leaves that turn burgundy in the fall. The flower color also changes from pink to dark burgundy.

Aspera is a large plant that requires shade. Its features are a rounded lacecap head with leaves that are fuzzy and oval.

Paniculata, or Peegee has eight inch long white flower heads that have a tendency to flop. It is the fastest growing and can reach twenty feet tall. A new cultivar, 'Tardiva,' has smaller flowers and doesn't flop.

Quercifolia, or Oakleaf Hydrangea is a fast growing shrub that grows to ten feet tall. The flower heads elongate up to twelve inches long.

"Oakleaf is most outstanding," says Ann, "it's a four-season plant. Unfortunately the deer like them. But, they're easy to grow and the flower lasts a long time."

Serrata has a Japanese origin and is usually a macrophylla lacecap that has come into its own class. It is similar to big leaf hydrangea but not in stature. It typically grows four feet tall and wide. Leaves are dark green and oval shaped. A new cultivar is 'Golden Sunlight', a lacecap variety which has leaves of bright yellow in spring that mature to light green by flowering time, then acquire a burgundy tint by fall.

Soil pH affects the color of your hydrangea, which range from pink, blue, and purple hues.

Kristina O'Connor of Wentworth Gardens says, "Maryland soil is acidic which will blue your hydrangea. If you want deeper blues you can add one heaping tablespoon of aluminum sulfate to a gallon of water and apply three times a year. If you want pink you need to raise the pH by adding dolomitic lime three to four times a year. Purple can be achieved by a balanced pH of 7. Changing the color of your flowers may take up to a year of amendments."

Other options for encouraging strong blues is a quarter ounce of sulfate of iron in a gallon of water applied in the spring and fall. Remember Grandma burying nails around the shrub? Dried blood is also good for intensifying color. Bone meal should be avoided when trying to achieve blue. And for you experts out there, your water's pH should not be higher than 5.6. One last note, if your hydrangea is planted near a concrete foundation or sidewalk the lime that leaches out of it will turn a blue hydrangea pink or purple. (White flowers cannot be changed by amendments.)

"Pruning is required only when your hydrangea gets too big," says Kristina. "Actually, pruning at the wrong time will cut off next year's bloom. If you must prune, treat it like an azalea and do it as soon as it finishes blooming."

Planting in the wrong place is a downfall to hydrangea, they like partial shade, where they are out of the sun between twelve and three o'clock. However avoid planting them in areas where there is large root competition.

"The best condition for growing hydrangea is consistently moist, but well drained soil. I also recommend mushroom compost if you have heavy clay soil. For sandy soil mix in organic matter and be prepared to water often."

For dried arrangements hydrangeas couldn't be simpler.

"The right time to cut," Ann says, "is late in the summer, when they're starting to dry naturally."