Hydrangeas offer masses of blooms all summer long and are among some of the hardiest low-maintenance shrubs for Pacific Northwest gardens.
With many species and cultivars, these deciduous shrubs start blooming in summer and continue up to the frost. This large group of plants includes different flower forms, climbing varieties, dwarf cultivars, plants with great fall color, and even selections with tolerance for sun and drought. The long-lasting blooms of hydrangeas even attract bees and butterflies! Hydrangeas are gorgeous in fresh flower arrangements, and the flowers can be dried to last for years to come.
New introductions of hydrangeas in recent years have brought larger flowers with richer colors, repeat blooming, and compact growth habits—finally! If you’ve wanted a hydrangea, but didn’t think your garden had enough space, you are in for a surprise. No matter the size of your garden or how much sun it gets, there is a hydrangea for you!
Read on for a summary of different hydrangea types to help you find the right one for your space.
Bigleaf Hydrangea (Hydrangea macrophylla)
Perhaps the most iconic hydrangeas, bigleaf hydrangeas are also known as mophead or lacecap hydrangeas and are fast-growing, rounded shrubs that begin blooming in early Summer with large flower clusters frequently lasting until Fall. Mature size varies by cultivar and can range from 2-3 feet up to 6-8 feet tall and wide. Hydrangea macrophylla prefers dappled sun or partial shade and thrives with regular moisture—you might say these put the “hydra” in Hydrangea!
Classic Bigleaf Hydrangeas are known for their ability to change color based on the pH of the soil (acid soil = blue flowers; alkaline soil = pink flowers; white flowers tend to remain white), though some new varieties tend to stay true to color. Old-fashioned varieties of H. macrophylla flower on previous year’s growth, making them sometimes tricky to prune, but “next generation” cultivars like the ‘Endless Summer’ series bloom on both old and new wood, extending the bloom season.
Below are some excellent, garden-worthy old-fashioned and new introductions of Hydrangea macrophylla:
‘Endless Summer’ Hydrangea – This cultivar was the first to offer reliable, repeating mophead blooms in light blue-violet coloration with sturdy stems; 3-4 feet tall by 4-5 feet wide.
‘BloomStruck’ Hydrangea – Prized for its repeat-blooming rose-pink to blue-violet mophead flowers, sturdy stems, disease resistance, and heat tolerance; features red-purple stems and great Fall color; 3–4 fet tall by 4–5 ft wide.
‘Blushing Bride’ Hydrangea – Has big, round, pure white semi-double flowers that mature to blush pink or soft blue; compact shrub with stronger stems; grows to 3–6 feet tall and wide.
‘Nikko Blue’ Hydrangea – One of the most popular and widely recognized varieties of bigleaf hydrangea; produces large, rounded flower clusters in intense blue color (prefers acidic soil conditions); rapidly grows to at least 6 feet tall and wide.
‘Summer Crush’ Hydrangea – A smaller mophead variety suitable for containers; grows 18–36 inches tall and wide; profusion of big raspberry red or neon purple blooms.
Summer Crush Hydrangea
Panicle Hydrangea (Hydrangea paniculata)
Panicle hydrangeas are low-maintenance and fast-growing large deciduous shrubs that are hardy from Zones 3 to 8. They feature elongated, cone-shaped blooms in white or ivory that last from mid-Summer into Fall and often change colors with age, usually finishing with shades of pink. Panicle hydrangeas are generally more tolerant of sun and heat compared to other species, and recent introductions have focused on drought-tolerance.
Hydrangea paniculata is gorgeous when used in mass plantings like borders or hedges. Tree-form standards of Panicle Hydrangeas can be used in pots or landscapes to provide height and structure. Single plants or small groups of H. paniculata are lovely when paired with grasses, lavender, or summer perennials.
‘Limelight’ Hydrangea – Highly regarded for large, cone-shaped flower heads that emerge lime green in mid-Summer and gradually turn creamy white and then blush pink as they mature until frost; known for strong stems and large stature, growing 6–8 feet tall and wide. A compact version of ‘Limelight’, ‘Little Lime’ Hydrangea grows to 3–5 feet tall by 3–5 feet wide and is perfect for smaller gardens or containers.
‘Diamond Rouge’ Hydrangea – A relatively new introduction, ‘Diamond Rouge’ boasts striking red stems and large, elongated flower clusters that start white and age to a rich, deep pinkish-red; grows 4–5 feet tall by 3–4 feet wide.
‘Vanilla Strawberry’ Hydrangea – Enormous, cone-shaped flower clusters start creamy white, gradually changing to blush pink and finally to deep strawberry red. New blooms emerge as older blooms change color, giving the plant a multicolored effect in late Summer and early Fall; grows 6–7 feet tall by 4–5 feet wide. For smaller spaces, try ‘Strawberry Sundae’ Hydrangea which grows 4–5 feet tall by 3–4 feet wide.
‘Quick Fire’ Hydrangea – Blooms about a month before other panicle hydrangea varieties and flowers every year! Flowers open white then turn pink as summer progresses. This super hardy shrub grows to about 6–8 feet tall and wide. For smaller gardens, try ‘Little Quick Fire’ Hydrangea, which grows 3–5 feet tall and wide.
Little Lime Hydrangea
Quick Fire Hydrangea
Oakleaf Hydrangea (Hydrangea quercifolia)
Oakleaf hydrangeas are upright, coarsely textured, large shrubs known for their oak leaf-shaped foliage. Later-blooming than macrophylla types, flowers tend to be cone-shaped and creamy white as they emerge in mid-Summer, slowly aging to shades of pink into Fall. The leaves have a colorful display in the Fall and turn orange, red, and burgundy in Autumn, and the bark peels with maturity, adding seasonal interest. These shrubs grow best in dappled or partial sun, but can tolerate full sun if given plenty of water.
‘Jetstream’ Hydrangea – Dense, compact shrub, growing to 5–6 feet tall by 4–5 feet wide; shiny dark green foliage is resistant to leaf spot and turns orange-red in Fall; white flowers on sturdy stems bloom in early Summer and age to pink; exfoliating tawny-brown bark adds winter interest.
‘Pee Wee’ Hydrangea – A compact dwarf cultivar ideal for smaller gardens or containers, growing to 3–4 feet tall and wide; feature large, showy flower clusters that start white and mature to soft pink; excellent fall foliage color.
‘Munchkin’ Hydrangea – Compact and well-suited for smaller landscapes at 3–4 feet tall and wide; enjoy a profusion of robust flower clusters that open white and age to pink on sturdy, upright stems; foliage turns brilliant mahogany in fall.
‘Ruby Slippers’ Hydrangea – This variety stands out for its compact size and vibrant flower color; cone-shaped flower clusters open white and gradually turn deep pink, resembling ruby-colored slippers; foliage turns a stunning burgundy in the fall.
Climbing Hydrangea (Hydrangea anomala petiolaris)
For shady, narrow areas with some vertical space, Climbing Hydrangeas are a perfect fit. Climbing Hydrangeas are self-clinging vines that can climb up walls, fences, or other structures. Slow to get established, this unique vine can eventually scale heights of 60–80 feet but can be maintained at smaller sizes with regular pruning.
Climbing hydrangeas offer fragrant, lace-cap style flowers in late Spring or early Summer, as well as attractive foliage, providing vertical interest and a distinct charm. Older stems develop a peeling texture and a cinnamon color. These hydrangeas can grow in partial sun or shade with adequate moisture, and do best on surfaces with east or north exposures.
‘Miranda’ Hydrangea – Known for its variegated foliage with yellow to creamy white margins, this vigorous vine clings to walls and can also be used as a groundcover; showy, fragrant, white blooms in late Spring to early Summer; features reddish brown bark for winter interest.
‘Pétiolaris’ Hydrangea – This is the species variety, often simply referred to as climbing hydrangea or Hydrangea petiolaris; features showy white flower clusters, heart-shaped dark green leaves, and exfoliating bark, adding winter interest to the vine.
Miranda Climbing Hydrangea
Smooth Hydrangea (Hydrangea arborescens)
Smooth Hydrangea is a rounded shrub featuring enormous white flowers (up to 12 inches across) blooming June through September on new wood. Hydrangea arborescens grows 3–5 feet tall and wide and is best cut back in late Fall or early Spring. Smooth hydrangeas love water and grow best in dappled sun or part shade, but will take more sun with sufficient moisture. This Hydrangea is native to the eastern United States.
‘Annabelle’ Hydrangea – One of the most well-known smooth hydrangea varieties; features exceptionally large, rounded flower heads composed of numerous white florets; known for its ability to produce abundant blooms and has sturdy stems that prevent the flowers from flopping over; resistant to slug and snail damage.
How to Prune Hydrangeas
Faded flowers on hydrangeas are best removed in Fall when the plant is done blooming, and it’s okay to remove some of the oldest twiggy branches to the ground each year or two or prune lightly to retain overall shape. To improve the structure on very old and overly leggy classic Mophead Hydrangeas, up to one third of the old stems can be cut back to the ground.
Heavy, aggressive pruning can ruin the flowering for the following year in many varieties. (‘Annabelle’ is the exception and can be cut to the ground in late Winter or early Spring). Consult an experienced pruner or seek local, expert advice before attempting substantial pruning.
Before major pruning is done, it’s important to know the three ways in which hydrangeas flower:
- Hydrangeas that flower on old wood (branches that have been on the plant since the Summer before current growing season)
- Hydrangeas that bloom on new wood (branches that develop during current growing season)
- Hydrangeas that flower on new and old wood (require little to no pruning!)
For hydrangeas that bloom on old wood – Prune only in the Summer before late August (before buds are set for next year). These hydrangeas produce flower buds in late August, September, or October for the following Summer’s blooms. If those stems are removed in Fall, Winter, or Spring, the bloom buds will be removed and there may be little or no flowers the following Summer. Includes: Hydrangea macrophylla ‘Nikko Blue’ or ‘Glowing Embers’, Hydrangea quercifolia
For hydrangeas that flower on new wood – Prune in late Summer or Fall after blooming or in Winter when dormant. Reduce growth as needed, remove the smallest branches, and prune to address both the size and shape of the plant. These shrubs should not be pruned in the Spring once new growth begins flower because you will cut off the flower buds. Includes: Hydrangea arborescens ‘Annabelle’, Hydrangea paniculata
For hydrangeas that flower on both new and old wood – Prune only if they’re getting too large for the space or to remove old flowers. The best time to prune is after they flower in late Summer. If you prune beyond late August, you will risk removing flower buds that are developing on current branches. Includes: Hydrangea macrophylla ‘Endless Summer’
How to Plant & Care for Hydrangeas
Hydrangea Sun Exposure
Most species of hydrangea are tolerant of full sun if given adequate moisture, but they are not suggested for areas with reflective heat such as against a sunny wall or on a hot deck or patio. The best exposure is east-facing in morning sun with dappled, late day sun or afternoon shade. Hydrangeas will grow in total shade, but often only flower lightly, if at all. Hydrangea macrophylla cultivars are generally most sensitive to hot sun, while Hydrangea arborescens ‘Annabelle’ and varieties of Hydrangea paniculata and Hydrangea quercifolia are more tolerant of sun and heat.
Hydrangea Soil Needs
Hydrangeas grow best in rich, well-draining soil—they do not like standing water or heavy clay soil conditions. They thrive in cool, coastal conditions, but if grown in sandy soil, watering may need to be done more frequently to avoid leaf scorch. Add organic soil amendments at planting time such as compost, peat moss, or decomposed manure to improve soil and create the rich, moist, well-draining conditions preferred. Mulch to keep roots cool and reduce water evaporation from soil surface—G&B Soil Building Conditioner makes a great mulch!
Flower color is affected by the pH of surrounding soil. Our native soil tends to be acidic; use a pH Soil Tester kit to check your native soil pH. Changing the color of hydrangea blooms can often take a few years to accomplish with more than one application necessary.
To change the pH of the soil, one must begin a full season or two before seeing desired results:
- Add lime to make soil more alkaline for pink blooms.
- Add aluminum sulphate (Hydrangea Blueing Formula) to make soil acidic for blue flowers.
- White flowers tend to remain white regardless of soil pH.
Hydrangea Water Requirements
Newly planted hydrangeas need regular watering until established (2–3 years)—water two to three times per week if planted in the ground and water daily if in containers. Established plants will grow best and flower more prolifically if given adequate moisture through the flowering period.
Supplemental watering done weekly during the hottest, driest months will keep plants looking their best. Plants exposed to hot, afternoon sun or reflective heat may show a partial wilt during mid-day sun, but this may not be an indication that they need water (I wilt in hot sun too!). Always check soil moisture levels before watering to avoid overwatering or causing disease problems.
Planting & Maintaining Hydrangeas
Ideal planting times for hydrangeas are Spring or Fall to give plants adequate time to establish healthy roots before the hot and dry conditions of Summer. It is best to fertilize hydrangeas at least twice per year—once in early Spring as new growth begins and again in late May or early June as flower buds appear and bloom cycle begins. A slow-release organic fertilizer such as G&B All Purpose Fertilizer is preferred over a synthetic such as 10-10-10, which often causes rapid growth and can lead to weak stems and floppy flowers.
Winter hardiness and cold tolerance of hydrangeas varies by species and cultivar. Hydrangea arborescens ‘Annabelle’ (USDA Zones 3-9) is widely planted throughout the United States due to its ability to tolerate temperatures below 0 degrees Fahrenheit. Most macrophylla types are hardy in Zones 6–9, while panicle and oakleaf varieties are slightly more cold-tolerant.
Hydrangea Pests & Diseases
Hydrangeas are relatively insect and disease resistant but can be prone to fungal diseases such as powdery mildew or leaf spot if grown in poor conditions. Some newer varieties have been bred for increased disease resistance. Aphids, spider mites, and caterpillars are the main pests and can all be easily handled with a basic insecticidal soap or with Captain Jack’s Deadbug Brew.
Long-blooming, easy-care, late-season color awaits you—stop in our garden centers to see these beauties for yourself!