What Is Oakleaf Hydrangea?
Oakleaf hydrangea (Hydrangea officinalis) is a shrub native to Europe and Asia. It grows up to 20 feet tall with long slender leaves that are dark green at the tips and pale yellowish brown at the base. The leaves have sharp spines along their edges which may cause irritation if touched or rubbed against your skin. They grow from the ground but they do not spread out like most other plants. Instead, they curl around each other forming a tight spiral shape.
The leaves of oakleaf hydrangea are very tough and can withstand cold temperatures well enough to survive without protection from frost. However, they do wither quickly so it’s best to prune them regularly when young.
You’ll notice that the leaves will drop off completely after just one winter season!
How To Care For Oakleaf Hydrangea?
Oakleaf hydrangea prefers full sun to partial shade. It does fine in part shade but it tends to become less vigorous than it would be in full sunlight. If you live where the weather is hot all year round, then oakleaf hydrangea might be too invasive and needs to go somewhere else. You’re best off planting it somewhere where it can spread out and not become a nuisance to you or anyone else.
The oakleaf hydrangea prefers moist soil but it’s tough enough to survive in clay and drought. It does well in most types of soil as long as it drains well.
You’ll get a more lush carpet of leaves if you keep the soil on the dry side during the growing season. Just be sure to give it an inch of water every week or so.
You can prune the oakleaf hydrangea at anytime of the year, but it’s best to do it in the winter and early spring. The plant only produces flowers on 1 year old wood so you’ll have to prune out all of the older branches that no longer have any leaves on them.
It’s best to cut them off right above where they join with the main stem.
It’s common for hydrangea leaves to become covered with mildew if the plant has been in the same location for many years. In fact, some people even think that mildew is a natural part of their heritage and characterizes them as hydrangea!
Fortunately it’s not necessary to use any sprays on your plants or wash them off with chemicals because there are several home remedies you can try. You can spray the leaves with a solution of one part milk and one part water. You can also spray them with a solution of one part vinegar and four parts water once a week until the problem goes away.
You should never fertilize oakleaf hydrangea because it causes the plant to produce more leaves and fewer flowers. Just be sure that it has good soil and enough water during the growing season.
If you live where the winters are very cold and you don’t provide any protection for your oakleaf hydrangea, you’ll surely end up with no leaves at all next spring! If this seems like something that might happen to you, then it’s best to take cuttings in the late fall or winter so you won’t have to suffer the loss.
Just be sure to keep the cutting moist and from freezing!
In The Landscape
The oakleaf hydrangea looks good in groups because the leaves form a very dense carpet of foliage. Even when they’re small, the leaves are thick enough that you can’t see the ground underneath.
It’s a great plant for planting under trees where nothing else will thrive because of the low soil fertility or excessive drainage.
The oakleaf hydrangea is a great choice for a naturalized area. It can also be a nice addition to a mixed border or even a shrub border if pruned regularly.
You can also plant it all by itself in a circle or some other shape to create a unique looking ornamental garden area.
This plant is a great choice for rain gardens and will actually thrive in them despite the fact that others won’t!
If you have a large group of oakleaf hydrangea, you might want to consider adding a bench or two around it so you can relax and enjoy their beauty.
Specimen or single feature plant
A colony of oakleaf hydrangea.
Scientific name: Hydrangea quercifolia
Common name: Oakleaf hydrangea
Family name: Hydrangeaceae
Habitat: Upland forests, stream banks, and thickets.
Growth habit: Large shrub or small tree that grows into a mound shape.
Foliage: Medium green leaves that are oval and toothed edges. Leaves are very thick and lush.
Root system: Deep taproot.
Stems: Small branches that are glossy brown in color.
Flowering season: Late spring into summer. Two types of flowers grow on separate plants.
One has a small white flower and the other has a small bluish-white flower.
Pollinator: Insects, especially bees.
Propagation: Seeds or hardwood cuttings. It’s difficult to propagate by seed.
The flowers are a favorite food of bees and the fruit is a favorite food of wildlife.
The fruit of the oakleaf hydrangea is a bladdery capsule that contains several semi-transparent brown seeds.
Flowers can be used in fresh or dried flower arrangements.
Hydrangea comes from two Greek words that mean “water container” and refers to the shape of the flower’s tube. Quercifolia means “oak leaf” and refers to the shape of the leaves.
Oakleaf hydrangeas grow in the wild in large groups that fill forests and form a dense understory. They are often used as landscape plants to replace trees in urban areas.
For a while, the oakleaf hydrangea was called the “invasive plant” from hell, but it’s actually not that invasive at all. In fact, it’s a very popular landscaping plant.
The main problem is that many people don’t know how to properly take “cuttings” or start new plants from the oakleaf hydrangea. Many people just pluck away at the stems and branches on their own plants and try to root them.
This doesn’t work very well because they aren’t freshly cut and the bark is damaged. Most of these stems and branches won’t take.
Sources & references used in this article:
A field guide to trees and shrubs: northeastern and north-central United States and southeastern and south-central Canada by GA Petrides – 1972 – books.google.com
Southern shade: A plant selection guide by J Kellum – 2008 – books.google.com
IPM FOR SHRUB PRODUCTION by EBYAMY FULCHER – ag.tennessee.edu
Plant life of Kentucky: an illustrated guide to the vascular flora by R Jones – 2005 – books.google.com
How to Prune Trees & Shrubs: Easy Techniques for Timely Trimming. A Storey BASICS® Title by GE Brown, T Kirkham – 2009 – Timber Press
Trees & shrubs of Kentucky by BW Ellis – 2016 – books.google.com
Llewellyn’s 2021 Herbal Almanac: A Practical Guide to Growing, Cooking & Crafting by CC Deam – 1924 – WB Burford, contractor for state …
Pruning trees and shrubs by ME Wharton – 1973 – books.google.com