17 Hydrangea Varieties You Should And Shouldn't Be Pruning In The Fall

To prune or not to prune? This may sound like an easy question. But if you're growing hydrangeas (Hydrangea), the answer is a little more complicated than you think. There are many tips and tricks for successful hydrangea blooms every year. Beyond giving your shrub fertile, moist, well-draining soil and partial shade, one of the most important tips is knowing when and how to prune your hydrangeas. With around 80 hydrangea species, some varieties bloom only on old wood, varieties that bloom only on new wood, and some that can bloom on both old and new. It's easy to see how this could get confusing. To know when to prune, you first need to identify which type of hydrangea you're growing. 

In general, most cultivars available for purchase can be traced back to six main types: bigleaf hydrangea (Hydrangea macrophylla), oakleaf hydrangea (Hydrangea quercifolia), climbing hydrangea (Hydrangea anomala subsp. petiolaris), smooth hydrangea (Hydrangea arborescens), panicle hydrangea (Hydrangea paniculata), and mountain hydrangea (Hydrangea serrata). Bigleaf, oakleaf, and climbing hydrangeas bloom on old wood, which means these plants create their flower buds on wood that is at least one year old. These flowers shouldn't be pruned in the fall, or you will end up stripping your shrub of new blooms for the upcoming season.

Meanwhile, smooth and panicle hydrangeas bloom on new wood, creating their flower buds on the current season's growth, meaning the shoots are less than 6 months old. You can prune these cultivars in the late fall, since their flower buds won't develop until the spring. Mountain hydrangeas and certain bigleaf hydrangeas can bloom on both old and new wood. These types of plants are usually called reblooming or remontant hydrangeas. 

'Limelight' (Hydrangea paniculata 'Limelight') is a late-blooming shrub providing pops of color for gardeners well into the fall. Flowering from July to September, the cone-shaped blooms open lime green, shift through creamy white, chartreuse, and pink, then fade to beige. Hardy in zones 3 through 9, this shrub reaches six to eight feet tall and wide.  Perfect for mixed borders, foundation plantings, and hedging, 'Limelight' tolerates full sun to partial shade. As a panicle hydrangea, its flowers bud on new wood, so you can safely prune in fall.

Hardy in zones 6 through 9, 'Nikko Blue' (Hydrangea macrophylla 'Nikko Blue') needs acidic soil to produce its rich blue hues. Known for its rounded petals that can grow four to five inches wide, 'Nikko Blue' usually starts blooming in June before stopping around August. Growing four to six feet tall, plant this beauty in an area with partial shade. As a mophead bigleaf hydrangea, prune 'Nikko Blue' in summer right after it finishes flowering.

Unlike most varieties, climbing hydrangea (Hydrangea anomala subsp. petiolaris) has a vining, spreading habit. Native to various regions in Asia, including Japan, China, and South Korea, these vines vertically climb areas like walls, fences, and other structures thanks to their habit of developing aerial roots along their stems. Once established, it can reach up to 50 feet, with a spread of five to six feet. Hardy in zones 4 through 8, this hydrangea type blooms on old wood. White lacecap flowers appear from May through July; prune soon after flowering, typically around July.

Hardy in zones 5 through 9, 'Gatsby Pink' (Hydrangea quercifolia 'Gatsby Pink') looks like a delicious, sugary confection. With cone-shaped flower panicles that turn from pure white into deep pink as the season changes. This oakleaf hydrangea will bloom from summer to fall. Its dark green foliage changes to shades of burgundy, purple, and red, providing your garden with some autumnal vibes. Native to the southeastern United States, 'Gatsby Pink' can grow between six and eight feet tall and wide. Since this cultivar blooms on old wood, prune after its flowers have faded, right before fall sets in.

This trademarked smooth hydrangea reaches four to five feet tall and wide. 'Incrediball' (Hydrangea arborescens 'Abetwo') features massive globular flowers that change from lime green to pure white as the plant matures. Hardy in zones 3 through 8, new flower buds emerge in June, before completing their bloom cycle in August. 'Incrediball' can tolerate full sun, but if you live in a hotter climate, try to plant this shrub in an area that gets partial shade. Blooming on new wood, it's safe to prune this plant in the fall. Though waiting until early spring is ideal. 

'Bluebird' (Hydrangea serrata 'Bluebird') is a compact mountain hydrangea with lacecap blooms. Growing as a dense bush, 'Bluebird' will reach five feet tall and wide. The delicate flowerhead has a central cluster of blue or pink florets surrounded by pale outer florets. Soil pH affects flower color: neutral or alkaline soils tend to produce pink flowers, while acidic soils shift color toward blue. Blooming from summer until fall, newer cultivars of this plant can bloom on old and new wood. Save any heavy pruning for right after flowering in the fall. 

From the trademarked Cityline series, 'Cityline Mars' (Hydrangea macrophylla 'Cityline 'Mars') is a small plant that packs a big wallop. One to three feet tall and wide, this compact bigleaf hydrangea is an excellent choice if you need a thriller in your mixed container garden. Hardy in zones 5 through 9, 'Cityline Mars' can also be used in foundation plantings and perennial gardens. If your soil is on the acidic side, your blooms will be blue, while alkaline soil will trigger pink blooms. 'Cityline Mars' blooms on old wood, but since it is so compact, there's no need for pruning. 

'Haas Halo' (Hydrangea arborescens 'Haas Halo') is a cultivar of the smooth hydrangea that can tolerate a little heat and humidity. Hardy in zones 3 through 9, the flowers of this perennial shrub will bring more pollinators into your yard and garden, attracting bees and butterflies. A quick grower, its white lacecap flowers will appear from June through July.  Though its blooming season doesn't last as long compared to other hydrangeas, the dried flower heads will remain until winter, providing interest. Because it buds on new wood, fall pruning is acceptable.

Producing massive conical flower heads propped on sturdy stems, 'Zinfin Doll' (Hydrangea paniculata 'Zinfin Doll') will begin its bloom cycle in mid-summer, which will last for over three months. Hardy in zones 3through 8, this type of panicle hydrangea reaches four to six feet tall and wide, growing in an upright, rounded habit. Its creamy white blooms will become pink as the season progresses. In colder climates, this shrub can handle at least six hours of sunlight. By fall, the blooms take on pinkish-red tones. Prune your 'Zinfin Doll' in the fall, since flowers bud on new growth.

One of the largest cultivars of oakleaf hydrangea, 'Alice' (Hydrangea quercifolia 'Alice') can grow between 8 and 12 feet tall. Hardy in zones 5 through 9, its pyramid-shaped panicles can reach up to 14 inches long. At the start of blooming season in June, its flowers open white before fading to pink, then brown. During the fall, its green leaves will change to bronze, maroon, and purple as the plant matures. Prune 'Alice' right after it completes its flowering season in July. If you wait until fall, you will strip new buds from second-year wood. 

'Endless Summer' (Hydrangea macrophylla 'Bailmer') is a coveted mophead hydrangea. This compact shrub will reach between three to five feet tall and wide. 'Endless Summer' features clusters of flowers that come in either blue or soft pink, depending on soil pH. Hardy in zones 4 through 9, 'Endless Summer' is extremely winter-tolerant. It is prized for a long bloom season, which can last from May to October. This cultivar blooms on old and new wood, which means you should avoid any pruning in the fall – wait until spring.

'Miranda' (Hydrangea anomala subsp. Petiolaris 'Miranda') is the variegated version of the climbing hydrangea. Hardy in zones 4 through 8, this deciduous climber can be used as a privacy screen or groundcover. Its foliage is marked by heart-shaped leaves with serrated edges. The yellow margins of its dark green leaves will fade to creamy-white. It can grow 50 feet tall with a 6-foot spread. White flowers will open around May and will continue blooming until early summer. Come winter, its bark will turn reddish brown. Because it blooms on old wood, do not prune your 'Miranda' in the fall.

A cultivar of the panicle hydrangea, 'Vanilla Strawberry' (Hydrangea paniculata 'Renhy') adds playful charm to any garden. Hardy in zones 3 through 8, this cultivar prefers a few hours of direct sun each day. Huge conical flowers will start to bloom in July and last until September. As the plant matures, its bloom will change from creamy-white to soft pink, before becoming strawberry red. This hue will last for four weeks before fading to brown. Growing up to eight feet tall and five feet wide, this cultivar blooms on new wood. Pruning in the fall won't compromise next season's blooms.

Small but mighty, 'Invincibelle Ruby' (Hydrangea arborescens 'Invincibelle Ruby') is a great option for mixed borders or as a flowering hedge. Staying between 36 and 48 inches tall with a 24 to 36 inch spread, this compact shrub will start blooming in the early summer. Its rounded, two-toned blooms emerge as burgundy buds before turning a mixture of bright ruby red and silvery pink. Hardy in zones 3 through 8, this smooth hydrangea is native to the eastern United States. Like all smooth hydrangeas, this cultivar blooms on new wood, making it safe to prune in the fall.

Hardy in zones 4 through 9, 'Tiny Tuff Stuff' (Hydrangea serrata 'Tiny Tuff Stuff') is another fantastic choice for filling a small space. Growing 24 inches tall and wide, this mountain hydrangea cultivar features double-petaled flowers and green foliage. Its flower buds are extremely hardy and cold-tolerant. Bloom season lasts from early to late summer, with petals in pastel blue, pink, or white; as the plant matures, blooms often fade to pink. 'Tiny Tuff Stuff' blooms on new and old wood, so it's best to avoid pruning it in the fall.

Hardy in zones 5 through 9, 'Pee Wee' (Hydrangea quercifolia 'Pee Wee') is one of the smaller oakleaf hydrangea cultivars. Reaching three to four feet tall and three feet wide, it's ideal for mass plantings, mixed shrub borders, or as a backdrop or accent plant. Its cone-shaped blossoms will appear in June, and the bloom season will last until July. Its flowers will open white before changing to a pink hue. The deep green foliage will gradually change to bronze, maroon, and purple by the fall. Blooming on old wood, avoid pruning in the fall.

'Invincibelle Mini Mauvette' (Hydrangea arborescens 'NCHA7') features dome-shaped flower clusters that come in shades of deep pink-mauve. Native to the United States, this small shrub will reach 36 inches tall and wide. If you're a gardener in a colder climate, 'Invincibelle Mini Mauvette' is pretty tolerant of cooler temperatures compared to other hydrangea varieties. Hardy in zones 3 through 9, it will start blooming in June before ending in September. As a smooth hydrangea that blooms on new wood, fall pruning is acceptable for 'Invincibelle Mini Mauvette.'