Hydrangea Culture

Useful hints for hydrangea growers

For success in the landscape the gardener needs to carefully select the planting location and pay close attention to the soil. Hydrangeas will not grow or flower satisfactorily in hot, dry, poorly drained locations.

There are two main types of hydrangea that are more commonly used as landscape plants. These types are the spring flowering and the oakleaf or native hydrangea.

Spring flowering…

The spring flowering hydrangea with its large pink or blue blossoms are most striking. This type has several different names such as Florist, House french, Bigleaf or Japanese Hydrangea. There are as many as fifty varieties that are bought as pot plants and then planted outside.

Plant…

Hydrangeas need a partially shaded or a northern exposure along with soil that is drained and contains plenty of organic matter or humus. For planting, dig a large hole approximately two feet across and one foot deep.

Fertilize…

Fertilize the plants in March, May, and July using one tablespoon per foot of height of 8-8-8 or 10-10-10 or a similar analysis fertilizer. Always thoroughly water the fertilizer into the soil.

Soil Acidity…

Flower color is determined by the acidity of the soil. In acid soils the flower will be blue, in a basic soil reaction or sweet soil the flower will be pink. If you have blue flowers and desire pink, apply lime at the rate of one cup per three foot plant. Sprinkle the lime under the plant and extending slightly beyond the drip line. A year may be necessary for a complete color change. A repeat treatment the following year may be necessary to complete the color change. For deep blue flowers use 1/3 cup of sulfur per three foot plant. Also, a teaspoon of alum aluminum sulfate) per gallon of water used as a drench in March, April and May will give you a deeper blue color.

Water frequently…

Hydrangeas need plenty of water so plan to water thoroughly once per week. More frequent watering may be necessary during hot dry weather.

The other of hydrangea grown is the oakleaf or native hydrangea with the coarse leaves and large white blossoms. Its color can not be changed.

For more information on hydrangea culture, contact your local County Extension Office.