Common Name: Oakleaf Hydrangea
Scientific Name: Hydrangea quercifolia
Order: Rosales
Family: Hydrangeaceae
Description Oakleaf hydrangea is a deciduous plant. Typically, it loses its leaves in the winter. During the winter season, oakleaf hydrangea will lose all of its leaves and flowers and remain bare until spring. The usual bloom time for oakleaf hydrangea is May-July. When blooming, the flowers are usually white but will change to a purplish-pink color. When describing the plant one must break down into foliage, flower, fruit, and trunk and branches. Oakleaf hydrangea has a simple, ovate shaped leaf with pinnate venation. The oak-like leaves are arranged in opposite pattern. Usual length of the blade is 8-12 inches long. During the fall, the leaves turn purple, but normally the leaves are green. Oakleaf hydrangea has a summer and spring flower with a natural pink coloring. The plant produces flowers in a pyramidal panicle form. The fruit is described as a small, brown oval with a dry, hard covering. Oakleaf hydrangea’s fruit has a diameter less than a half of an inch. Its branches grow in an upright position and have a thick, brown, and multi-stemmed structure.
Growth Habit The average height of oakleaf hydrangea is 6-8 feet. The spread in diameter is 6-8 feet. Since it is a multiple stemmed plant, there are several stems that originate from the ground. Oakleaf hydrangea has a fast growth rate of 7 months. Oakleaf hydrangea is a perennial plant, meaning that this plant will be able to grow continuously for many years. If the plant is properly taken care of then there is no need to uproot and replant another oakleaf hydrangea.
Hardiness Zone(s) The USDA zones for the oakleaf hydrangea are zones 5B through 9. Oakleaf hydrangea originated from Florida. According to the USDA, it is native to the lower 48 United States. Usually, oakleaf hydrangea is most commonly found in the Southeastern United States. It is a very hardy plant that only starts to lose its flowers or buds when temperatures reach below -10˚F. These extreme conditions damage the plant and prevent blooming for the following year.
Culture Oakleaf hydrangea is a low maintenance plant. This plant thrives on well-drained, organically rich, moist soils. The ideal pH level for oakleaf hydrangea is ranges from 6.8 to 7.2. Usually during the summer, mulch used to help maintain moisture in the soil. They require a medium water intake. Oakleaf hydrangea favors a full to partly shaded area. This plant requires little pruning and should be allowed to grown in its natural form. Only prune oakleaf hydrangea if one has to reduce or reshape the plant. Oakleaf hydrangea can be pruned in the early spring, but only if there are any damaged stems from the winter. July is the final month that any necessary pruning may occur. This is to allow growth of flower buds for the following year. When oakleaf hydrangea is grown in zone 5, the plant should have some sort of protection from the harsh winter, especially when the plant is not fully developed.
Diseases & Insects There are very few problems with this species in regards to diseases and insects. One example of a disease found in the plant is of leaf bright. The signs of leaf bright are streaks or necrotic spots are found throughout the plant’s leaves. Another disease that is found in oakleaf hydrangea is a powdery mildew. This describes the white chalky type of fungus that is on the plant leaves. With regards to insects, oakleaf hydrangea has few problems. Some examples of insects that affect oakleaf hydrangea are aphids and spider mites.
Landscape Value Oakleaf hydrangea is a diverse species that has a wide range of foliage, flower, and growth features. This plant can be found in various shapes and sizes due to its high tolerance to the environment. This diverse plant can be used in various ways. Some examples include foundation, mass planning, climbing vines, specimen plants, shrubberies, and perennial borders.
References Gilman, E. F. 2015. Hydrangea quercifolia; Oakleaf Hydrangea. University of Florida Institute of Food and Agricultural Sciences, EDIS. Online.
This document was authored by Lauren Dartez, Department of Agricultural Sciences, Louisiana Tech University, April 2015.