Oakleaf Hydrangea
Flowers, Fall Color and Winter Interest
This low-maintenance shrub has it all!
Oakleaf hydrangea (Hydrangea quercifolia) is an upright, irregularly shaped deciduous shrub grown for its four seasons of interest - striking spring and summer flowers, rich fall color, and beautiful exfoliating bark. This shrub is native to the moist woods and stream banks of the Southeastern United States and grows well in zones 5-9. The oakleaf hydrangea gets its name from the large, deeply lobed leaves resembling those of an oak tree. Numerous different cultivars are available, providing options in terms of size and flower color.
The showy, panicle-shaped flowers of oakleaf hydrangea emerge bright to creamy white in the springtime and gradually turn shades of pink, rose or green, depending on the cultivar. In autumn, the large, oak-like leaves turn stunning shades of red, purple and burgundy. Mature plants have striking cinnamon-colored exfoliating bark, which provides interest in the winter landscape.
Oakleaf hydrangeas are relatively easy to grow. They prefer moist, rich soil in full sun to partial shade. Established plants can tolerate some drought (Are you in a drought? Check the U.S. Drought Monitor). These slow to moderate growers appreciate a layer of mulch to keep their roots cool, and most cultivars will reach 4-8 feet high and wide in maturity. Deer will occasionally eat oakleaf hydrangeas, especially the tender new leaf tips that emerge in early spring.
Oakleaf hydrangeas bloom on old wood and look their best with minimal pruning. If needed, prune in mid-summer when flowering has finished. Dried flower heads remain on the plant, adding visual interest to the fall and winter garden. Oakleaf hydrangeas are easy to grow and generally disease and insect free. On occasion they may be bothered by aphids, spider mites or powdery mildew.
How to Plant and Grow the Oakleaf Hydrangea
Location: Choose a site with moist, fertile, well-draining soil and full sun to partial shade - oakleaf hydrangea needs some sun to bloom.
Planting: The best time of year to plant an oakleaf hydrangea is in the spring or fall, giving the roots time to establish before the onset of extreme hot or cold weather. Water deeply, immediately after planting.
Watering: Keep the soil consistently moist, especially during the first two growing seasons. Though oakleaf hydrangeas are drought tolerant once established, they prefer moist soil and benefit from regular watering, particularly during dry periods (See “How to Water Your Plants” for help in determining a watering schedule).
Mulch: Apply a layer of organic mulch around the base of the plant to retain moisture, suppress weeds, and regulate soil temperature.
Pruning: Oakleaf hydrangeas bloom on old wood and look their best with minimal pruning. If needed, prune in mid-summer when flowering has finished. Avoid pruning in late summer, fall, or winter, as you risk removing next year’s flower buds.
Fertilizing: In springtime, apply a top dressing of compost, leaf mold, or Leaf-gro® to the soil around your oakleaf hydrangea. This will help to create the rich, fertile soil these shrubs love.
In fall, the leaves of Oakleaf Hydrangea turn a deep burgundy red.
Landscaping Ideas for the Oakleaf Hydrangea
Choose cultivars based on their mature size, so they don’t outgrow their space.
Woodland’s edge: Soften the transition from lawn to forest with oakleaf hydrangeas.
Mass planting: For a dramatic effect, group multiple oakleaf hydrangeas together in a mass planting. This works well in larger garden spaces and can make a bold statement.
Mixed Border: Create a mixed border planting by combining oakleaf hydrangeas with other flowering shrubs and perennials.
Informal hedge: A row of oakleaf hydrangeas can soften the look of a backyard fence or chain-link fence, or can be used to delineate property lines.
Foundation planting: For year-round beauty, combine oakleaf hydrangeas with evergreen shrubs along the foundation of your home.
Specimen or accent plant: Oakleaf hydrangeas make a great stand-alone specimen or accent plant.
Containers: Dwarf cultivars like ‘Little Honey’ can grow in containers on a patio, front porch, or deck. Use a pot with drainage holes, and be sure to water frequently - containers dry up quickly.
Oakleaf Hydrangea Cultivars
Alice (Hydrangea quercifolia ‘Alice’): Large white flowers age to pink, and a more vibrant fall color than the original species. Reaching 10-12 feet tall, ‘Alice’ needs plenty of room to grow, making it a good choice for larger spaces and yards that back up to wooded areas.
Amethyst (Hydrangea quercifolia ‘Amethyst’): White flowers age to wine red, and brilliant burgundy fall color. Grows 4-5 feet tall and 6 feet wide.
Gatsby Gal (Hydrangea quercifolia ‘Gatsby Gal’): Pure white flowers on a compact plant, growing 5-6 feet tall and wide. A great choice for smaller yards.
Gatsby Moon (Hydrangea quercifolia ‘Gatsby Moon’): Large white flowers with double florets turn green as the season progresses, followed by burgundy-red fall color. Grows 6-8 feet tall.
Gatsby Pink (Hydrangea quercifolia ‘Gatsby Pink’): Dark green foliage and showy white blooms that quickly turn pink. Grows 6-8 feet tall and wide.
Little Honey (Hydrangea quercifolia ‘Little Honey’): A dwarf cultivar with lime green leaves and white flowers, growing 3-4’ tall, and 4-5’ wide. Requires more protection from the hot afternoon sun. Great for container plantings.
Munchkin (Hydrangea quercifolia ‘Munchkin’): A small, compact grower reaching 3-4 feet high and wide. Flowers emerge white and turn shades of ruby pink in autumn. Great for size for foundation plantings, especially underneath windows.
Pee Wee (Hydrangea quercifolia ‘Pee Wee’): A great size for small yards and foundations plantings, growing 3-5 feet high and wide. Has a round, compact form and white flowers fading to pink (not to be confused with the popular ‘Pee Gee’ panicle hydrangea, Hydrangea paniculata ‘Pee Gee’, which is a different type of hydrangea).
Ruby Slippers (Hydrangea quercifolia ‘Ruby Slippers’): Flowers emerge white and quickly turn deep pink, remaining upright on strong stems. Makes a great informal hedge or border, growing up to 4 feet tall and 5 feet wide.
Snowcicle (Hydrangea quercifolia ‘Snowcicle’): Tricolor flowers in shades of rose pink, cream, and green top strong stems bred to resist flopping. Grows 4-6 feet tall and wide.
Snowflake™ (Hydrangea quercifolia ‘Brido’ Snowflake™): Notable for its showy, sterile, double white flowers. Growing 5-8 feet tall and up to 10 feet wide, it needs space to spread out.
Snow Queen (Hydrangea quercifolia ‘Snow Queen’): Similar to ‘Alice’, growing up to 6 feet high and wide with abundant dense white flowers turning pink as the season progresses. A great candidate for the back corner of a border garden.
The bold leaf shape of oakleaf hydrangea (Hydrangea quercifolia) contrasts nicely with soft mosses, landscaping rocks, and the small shiny leaves of Himalayan sweet box (Sarcococca hookeriana var. humilis).
Why isn’t My Oakleaf Hydrangea Blooming?
If a once thriving oakleaf hydrangea stops blooming, it could be due to improper pruning, insufficient sunlight, and over-fertilization:
Improper pruning: Oakleaf hydrangeas set their flower buds on old wood. Prune oakleaf hydrangeas in mid-summer, when flowering has finished for the year. If you prune in late summer, fall, or winter, you will cut off the buds for next year’s flowers and the shrub will not bloom. Better yet, just leave these plants alone - they don’t need much pruning, except for dead or dying branches.
Insufficient sunlight: Oakleaf hydrangeas grow in full sun to partial shade, meaning they require at least 4 hours of direct sunlight per day to flower. Direct morning sun and afternoon shade work best. If your plant has too much shade, it will not flower.
Over-fertilization: An excess of nitrogen from fertilizer will result in lush foliage growth but no flowers. Oakleaf hydrangeas generally do not require fertilizing. Instead, spread compost, leaf mold or Leafgro® around the base of your plant each spring to create the rich, fertile soil these shrubs love.
Should Oakleaf Hydrangeas Be Cut Back in the Fall?
Oakleaf hydrangeas should not be cut back in the fall. If you cut back or prune an oakleaf hydrangea in the fall, winter, or spring, you will cut off the buds that will become next year’s flowers and the shrub will not bloom.
Oakleaf hydrangeas bloom on old wood and look their best with minimal pruning. If needed, prune in mid-summer when flowering has finished. Dried flower heads can be left to remain on the plant through fall and winter, providing interest in the winter landscape.
Are Oakleaf Hydrangeas Poisonous to Dogs?
Oakleaf hydrangeas (Hydrangea quercifolia) contain compounds that can be toxic to dogs if ingested, specifically cyanogenic glycosides. These compounds can release cyanide when broken down in the digestive system. However, the level of toxins in oakleaf hydrangeas are relatively low, and instances of dogs getting poisoned by consuming these plants are rare.
While the risk of severe poisoning is low, it’s important to monitor your dog's behavior in outdoor spaces. If you suspect your dog has ingested a toxic plant, seek immediate veterinary care or contact the Pet Poison Hotline (read “Which Plants are Toxic to Dogs” for more information).
Do Oakleaf Hydrangeas Spread? Are Oakleaf Hydrangeas Invasive?
Oakleaf hydrangeas are not classified as an invasive plant in the United States. They are native to the southeastern part of the country, where they can be found growing in moist woodlands and along stream banks. Oakleaf hydrangeas are planted widely in urban and suburban landscapes, and do not cause harm to the environment, humans, animals, nor the economy.
Oakleaf hydrangeas are generally well-behaved plants and do not seed aggressively. They will spread by stolons, sending up new shoots and forming a colony over time. If you notice your oakleaf hydrangea sending up new shoots from the ground in spring, it means you have a happy plant. Well done!
