Good Hydrangea for Oklahoma

Description

• Bigleaf hydrangea has white, pink, red or blue flowers. It can be a large bush, growing to be 3 to 6 feet tall and 3 to 6 feet wide. As the name suggests, this plant has large leaves. There are two main groups of bigleaf hydrangea: hortensias, sometimes called mopheads, which have big, snowball-like clusters of flowers; and lacecapes, which have lacy looking flower clusters.

Requirements

• The plant, native to Japan, grows well in US Department of Agriculture hardiness zones 6 through 9. Oklahoma is located in USDA zones 6 through 8, so this hydrangea is a good choice for Oklahoma gardens. Bigleaf hydrangeas need well-drained moist soil and need some protection from extreme heat. They can thrive in partial or full sun; ideal conditions call for morning sun and afternoon shade. Before planting, work compost into the top 8 to 12 inches of soil. Water thoroughly after planting and keep it well-watered, especially when first planted. Bigleaf hydrangea needs to be fertilized several times during the growing season. During the winter, cover it with a sheet or blanket when the temperature drops below freezing.

Change the Blossom Color

• Flower color can sometimes be changed from pink to blue and from blue to pink by altering the chemical composition of the soil. For blue flowers, the soil needs to be acidic with a pH level of 5.0 to 5.5. By adding a half an ounce of aluminum sulfate to one gallon of water and applying it to the plants after watering with pure water, gardeners can increase the acidity of the soil to the appropriate level for blue. It's harder to change blue to pink, but by adding dolomitic lime to the soil several times a year, the pH can be increased to 6.0 to 6.2, which is the level for pink blossoms. Choose fertilizers with a high phosphorus rate, 25/10/10, for pink and a low phosphorus rate and high potassium rate, 25/5/30, for blue. White blossoms will always stay white and cannot be changed.

Drying Hydrangeas

• Hydrangeas can be cut when fresh to make into bouquets, and they can also be used in dry arrangements. They should be allowed to dry on the bush and harvested after they have turned light green with hints of burgundy and pink. After picking, remove the leaves and arrange the hydrangeas in a vase or other container. The flowers can be dyed or left natural.