Hydrangeas are a type of flowering plant. It is a genus that is comprised of between 70 and 75 different species of plants. Hydrangeas originate in Asia (East and South regions) and the Americas (North and South). Only five varieties of hydrangeas are widely cultivated within the United States. Hydrangeas can be either small trees or shrubs. The majority of them are shrubs. The plants are either evergreen or deciduous.
The majority of hydrangea species are white. However, there are some species, such as the Hydrangea macrophylla, that can produce a more diverse array of colors, such as pale purple, deep purple, pink, red and blue. They appear in flowerheads (either panicles or corymbs) on the ends of stems. Hydrangeas often grow to between 4 and 6 feet in height.
Hydrangeas are relatively easy to cultivate. In gardens, they thrive in protected areas away from the wind, either in filtered sun or partial shade. For flowering, sun is necessary. They prefer a high-quality loam and moisture without sogginess. A pH level of 6.7 is preferable with hydrangeas.
Diseases and Pests
As with any plants, hydrangeas are susceptible to some diseases and pests. Some diseases that could cause damage to hydrangeas include Cercospora leaf spot, powdery mildew, botrytis blight, anthracnose, phytophthora root rot and mushroom root rot. Some pests that could be bothersome or destructive to hydrangeas include mites, aphids and Japanese beetles.
There are many cultivars of hydrangeas. Some well-known and popular varieties of hydrangeas include the Hydrangea heteromalla, Hydreangea integrifolia, Hydrangea involucrata, Hydrangea anomala, Hydrangea paniculata, Hydrangea stenophylla, Hydrangea longipes, Hydrangea serratifolia, Hydrangea xanthoneura and Hydrangea lingii.
Hydrangeas are popular ornamental plants due to their attractive and bright appearances. They are cultivated for their big flowerheads and are common additions to gardens. Homeowners should be careful with hydrangeas in their gardens, however, as the plant is mildly toxic if consumed. All sections of the plant consist of cyanogenic glycosides. It is important to keep small children and pets away from hydrangeas in gardens.