Hydrangea aspera is a deciduous shrub native to China, Taiwan, India, and the Himalayan region. Its showy flowers make it stand out from the other members of the hydrangea family. The two main varieties of hydrangea aspera are villosa and sargentiana. These ornamental hydrangeas require moist soil and thrive in sun or partial shade. Plants can be propagated from seeds or cuttings.
The flowers of the hydrangea aspera contain white or pink blossoms bordered by pink, white, lilac, or purple blooms. These striking flower clusters are approximately 10 inches (25.5 centimeters) across, and bloom in late summer and early fall. Like other hydrangeas, the coloration of the hydrangea aspera flowers depends on the acidity of the soil. Flowers can be found in various hues of white, pink, and purple. Adding aluminum to the soil will cause the flowers to turn blue.
Hydrangea aspera reaches a height of 10 to 12 feet (3 to 3.5 meters) with the same amount of spread. It has a peeling bark with a brown to brownish-gray color that adds interest to the landscape during the colder months when the leaves are gone. Found in both cold climates and tropical regions, the plants vary in their tolerance to cold.
Leaves of the hydrangea aspera are around 10 inches (25.5 centimeters) long and 4 inches (10 centimeters) wide. They are shaped like lances with a serrated edge, and are dark green with a fuzzy coating that feels like velvet. The large, dark leaves provide a stunning contrast to the brilliant flower clusters.
These plants should be pruned during their months of dormancy, or they can become leggy. Overzealous pruning or pruning when the plant isn’t dormant can harm the plant. Other threats to hydrangea aspera are honey fungus and early frost. The area surrounding the plant should be maintained free of pests and weeds to prevent the fungus from forming, and the plant should be covered at night if early frost is predicted. Although the soil should be kept moist, overwatering can harm the plant, so good drainage must be maintained.
Hydrangea aspera has had limited use as a medicinal plant. Some have ingested tea to treat digestive and respiratory problems. A few claim that it is beneficial in treating cancer. Caution should be exercised when making an infusion of this plant because the leaves contain hydrogen cyanide. This causes respiratory failure when ingested in large quantities, which can be fatal.