Plant Hydrangeas for Large, Long Lasting Blooms
What shrub could be as generous, as beautiful, or as versatile as the hydrangea? A wide growing shrub with big leaves, hydrangeas bloom as early as late June and hold on to their flowers until fall.
Mophead, Lacecap, Pee Gee, and Oakleaf hydrangeas offer large blooms of tiny flowers in white, pink, violet, blue, green, and variations in between. Some blue green flowers show pink at the edges, or pink flowers are touched with violet. Some blue flowers turn greenish or teal toward the end of the season.
Hydrangeas make fabulous wedding bouquets and floral arrangements. Sometimes, a single stem is all you need. The extravagant nature and large size of hydrangea blooms make them a great choice any time you use cut flowers. Make sure that you cut blooms early in the morning.
Hydrangeas dry well. For dried hydrangeas, cut blooms in late summer, when the bloom has naturally dried on the shrub. Unlike most spent blooms, the flowers of the hydrangea age well and retain their beauty long after their peak.
You can hang hydrangeas upside down to dry, or merely place them in a dry vase. Dried hydrangeas are usually a mix of several colors and their muted hues make for a nice vintage look. Dried hydrangeas are also great for making wreaths.
Mophead hydrangeas are the most common form of this popular shrub. A large growing shrub up to 4' tall and as wide or wider, mopheads feature huge, rounded blooms. Mopheads need no pruning, except for the removal of dead or damaged branches.
If you want to prune for size, cut back in the summer. Pruning in fall or spring will interfere with bloom production the following year, as new buds are set soon after flowering.
In hotter climates, mophead hydrangeas generally age toward a pinkish green in late summer. In cooler areas, the blooms fade to a violet or blue.
Do not plant mophead hydrangeas under trees as tree roots interfere with water absorption. Heavy, overhanging trees may provide too much shade. Mopheads prefer morning sun and afternoon shade.
Pink or Blue Mophead Hydrangeas
Pink or blue hydrangeas are influenced by the soil's pH. Use a soil tester kit to determine your soil's pH. Chances are, you know if your soil is acid or alkaline.
The presence of aluminum in acid soil creates blue hydrangea blooms. The acid soil (pH 5.2 - 5.5) helps hydrangeas to take up aluminum. Use a fertilizer that is high in potassium and low in phosphorus (25/5/30) if you want blue blooms. You can add Aluminum sulfate by mixing one tablespoon to a gallon of water. For blue blooms, mulch with shredded pine bark, pine needles, or coffee grounds. Nikko Blue is one of the best blue hydrangeas and does well in shade, growing between 4 - 6' tall.
It is not unusual to see different colored blooms all on one shrub.
Pink hydrangea blossoms are produced with an alkaline soil (pH 6.0 - 6.2). To increase the pink color, add lime to the soil and use a fertilizer that is high in phosphorus (25/10/10). You can increase alkalinity by placing broken pieces of concrete around, not touching, the base of the plant. Or, plant hydrangeas between a cement foundation and sidewalk to enhance the alkalinity of the soil with lime.
It is easier to intensify the color naturally produced by the soil in your area. The addition of too many chemicals or too strong of a mixture can harm shrubs.
Feed mop-head hydrangeas in late winter or early spring. Add compost and mulch to retain moisture. Newly planted hydrangeas may need watering daily in dry, hot weather.
The blooms of white or cream colored hydrangeas can not be altered. The color of lace-caps can be influenced in the same way as mopheads.
Lacecap hydrangeas feature flattened, rounded blooms with tiny, tightly packed flowers in the center, encircled by larger flowers typical of mop-heads. Treat lacecaps the same as mopheads.
Lacecaps are not as common as mopheads but respond to the same color influences. They grow from 3-5' tall.
Pee Gee or Paniculata Hydrangea
Pee Gee or Hydrangea paniculata does well in full sun and hot weather. This large growing shrub can be pruned any time of the year into tree shape. White blooms in late summer often turn pink with age.
Paniculata grandiflora is a popular variation with huge, white blooms and is the source of the nick name, Pee Gee. Paniculata grows up to 10' tall and is often used as a focal point, due to its old fashioned charm and striking good looks.
Oakleaf hydrangeas grow in sun or partial shade but will do better in hot areas with a bit of afternoon shade. Oakleaf hydrangeas require excellent drainage as too much moisture will rot the roots.
This US native produces beautiful white blooms and is more suited to to dry weather than mopheads. The blooms are not rounded, but conical spikes of many small flowers.
Oakleaf hydrangea gets its name from the leaves which resemble oak leaves and not at all like the standard, heart shaped hydrangea leaf. The foliage turns bronze, red, or purple in fall.