HYDRANGEAS: GREAT BALLS OF FLOWERS.

Byline: Karen Dardick Correspondent

If huge clusters of flowers appeal to you, try growing hydrangeas.

These shrubs are easy to grow, even in the hottest parts of the Valley. They will flower continuously from spring through fall with minimal care.

Their virtues include a profusion of large-cluster flower heads. They flourish in shady and semi-shady areas of the garden to create stunning displays. They're rarely affected by insects or diseases.

``What can be easier to grow?'' asked Kate Karam, manager of Hortus, a Pasadena nursery that stocks more than 60 different hydrangea varieties.

``Just plant them in partial shade, water regularly and throw a little fertilizer on the shrub twice a year and you'll have huge clusters of flowers to enjoy in a garden or in a vase.''

Most people think of hydrangeas as those tall shrubs with big pink flower clusters. But that's just one example of a shrub family that ranges in size from 18 inches to 50 feet. There are hundreds of named varieties of Hydrangea macrophylla, commonly known as big leaf or garden hydrangea. The most commonly grown are the type known as mophead, and the most popular variety is ``Nikko Blue,'' which often is pink in our alkaline soil.

``There's a whole other world out there of hydrangeas for people to try,'' Karam said. ``Some varieties grow as vines and can cover buildings or trees, others are great as standards, and some are small front-of-the-border plants.''

She especially likes lacecap hydrangeas, so-called because their clusters are more open and lacy. ``They're sophisticated and modern,'' Karam said.

Oakleaf hydrangeas have deeply lobed leaves that resemble those of their namesake trees. They perform well in heat and are excellent container plants.

You can also find an interesting assortment of flower colors besides pink. White, blue, purple, light purple and brilliant red flowers make hydrangeas even more fascinating garden additions.

Hydrangeas are deciduous and lose their leaves and visual appeal in late fall. When selecting a location for planting or placing in containers, you may want to grow them where they won't be a specimen plant at their most unattractive time. They mix well with camellias, which come into bloom when hydrangeas are dormant.

Whatever variety you select, follow these simple steps for success:

1. Plant in a semi-shady location where the plant is protected from wind and sun.

2. Amend soil with liberal amounts of organic material so it's fast-draining. If planting in a pot, use camellia-azalea potting mix with regular potting soil in a 50-50 ratio.

3. Water regularly to a depth of 24 inches. Once a week is usually enough for hydrangeas planted in the ground, unless temperatures soar.

Container plants dry out faster and may need watering two or three times a week.

4. Fertilize in January and again in May with camellia-azalea fertilizer. A dose of fish emulsion in June will enhance flower production for fall.

5. Be brave when it's pruning time in November. Remove at least 2/3 to 3/4 of the plant to ensure that next year's stems will be sturdy and strong enough to support the large flower heads. However, since hydrangeas form their flowers on stems from the previous year, be sure to leave enough stem length for showy flower effect.

Hydrangeas with pink flowers can be encouraged to turn blue with the addition of aluminum sulfate. When planting, add several cups of aluminum sulfate and work well into the soil. Repeat several times a year, but use just one cup of aluminum sulfate each time, and work into the soil.

Choosing your hydrangeas

Best hydrangeas, as recommended by Kate Karam:

Alpengluhen (Glowing Embers) - Red

Altona - Red, blue and green flowerets that turn pink or blue in late season

Ayesha - Delicate pale pink or mauve petals

Bluebird - Blue

Blue Wave - Blue

Lanarth White - White

Madame Emile Mouillere - White

Pink Diamond - Pink

White Wave - White

Hydrangea aspera Villosa - Blue violet

Hydrangea paniculata Burgundy Lace - Wine red

Hydrangea paniculata Peegee

Hydrangea petiolaris - Climbing variety, white.

Show off your hydrangeas

In a vase:

Hydrangea flowers can last a long time in a vase when they are well-hydrated. Here's how:

1. Cut flower heads with long stems and place in vase of cool water that covers the entire stem length.

2. Drape white paper towels over the flower head.

3. Mist heavily with cold water.

4. Continue the process for two hours before removing paper towels.

Flowers should last up to two weeks because they can absorbed water through their entire length.

In dried flower arrangements:

You can also prepare hydrangeas for use in dried arrangements.

1. Cut long stems and remove all leaves.

2. Put in a deep vase with 2 inches of water and place in a closet or other dry, cool location.

3. Leave until all the water is absorbed. Flowers will retain their color and shape indefinitely. They can be used in dried arrangements until they get crispy and start to disintegrate.

CAPTION(S):

3 photos, 2 boxes

Photo:

(1 -- color) ``Forever Pink'' hydrangeas show off a summer bloom at Pasadena's Hortus Nursery.

(2 -- color) These hydrangeas, at Hortus Nursery in Pasadena, flourish in shady garden areas and are seldom affected by insects or disease.

(3) Jesse Aguirre waters the hydrangeas at Hortus Nursery in Pasadena. There are hundreds of varieties of the shrub, ranging in size from 18 inches to 50 feet.

L.J. McAllister/Special to the Daily News

Box: (1) Choosing your hydrangeas

(2) Show off your hydrangeas