Illustration
Oakleaf Hydrangea
Hydrangea quercifolia
Oakleaf Hydrangea blooms from May through July.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Oakleaf Hydrangea
Plant it in part sun. It prefers moderate water. It is hardy in USDA zones 5–9. Expect it to reach about 6 ft tall and 6 ft wide at maturity, in roughly 4 years (not yet checked).
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Oakleaf Hydrangea
Plant Oakleaf Hydrangea in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 7, the middle of its hardy zones 5 to 9, spring means March to May and fall means September or October. Once settled, it blooms from May to July.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 7, the middle of this plant's hardy range, start with zone 7 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Oakleaf Hydrangea get?
6 fttall5 ft 7 inan adult6 ftwideSee Oakleaf Hydrangea in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Oakleaf Hydrangea
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Oakleaf Hydrangea about 6 ft apart, center to center, so each plant has room to reach its full width.
Add Oakleaf Hydrangea to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Oakleaf Hydrangea's height, spread, hardiness zones, sun and trait tags were checked against 14 published sources on July 31, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- brighterblooms.comBrighter Blooms Nurseryheight, spread, hardiness zones, sun, years to mature size and trait tags
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun, years to mature size and trait tags
- The Morton Arboretumheight, spread, hardiness zones, sun, years to mature size and trait tags
- Missouri Botanical GardenPlant Finderheight, spread, hardiness zones, sun and trait tags
- University of Florida IFASUF/IFAS Gardening Solutionsheight, spread, hardiness zones, sun and trait tags
- University of Florida IFASUF/IFAS EDIS FPS-259 Hydrangea quercifolia Oakleaf Hydrangeaheight, spread, hardiness zones, sun and years to mature size
- aces.eduAlabama Cooperative Extension Systemheight, spread, hardiness zones and sun
- RHSRoyal Horticultural Societyheight, spread, sun and years to mature size
- Chicago Botanic GardenPlant Finderheight, hardiness zones and sun
- homegarden.cahnr.uconn.eduUConn Home Garden Education Center hydrangea factsheetheight, hardiness zones and sun
- piedmontmastergardeners.orgPiedmont Master Gardeners (Virginia Cooperative Extension)hardiness zones, sun and trait tags
- plantdatabase.uconn.eduUConn Plant Databaseheight, hardiness zones and sun
- Mississippi State University ExtensionServiceheight and sun
- Clemson Home and Garden Information CenterClemson Cooperative Extension HGIC 1067height
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Oakleaf Hydrangea
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Toxic to dogs, cats and horses; the leaves and buds hold a cyanogenic glycoside. Eating it mostly causes vomiting and diarrhea. per ASPCA
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.