The Best Hydrangeas for Your Climate: Tips for Your Zone

Hydrangeas add bountiful blooms to the landscape, with summer flowers that overflow amongst a leafy backdrop. These elegant and classic beauties feature exciting colors in various bloom shapes and forms, as well as varying plant sizes and growth habits. 

Hydrangeas possess unique characteristics, from long bloom times to fall color and winter interest. They’re versatile shrubs that grow across most hardiness zones and are beautiful in mass plantings, as hedges, and as specimen selections. There’s no shortage of new cultivars to explore, from color-changing flowers to compact and sturdy forms, along with charming favorites. 

With exceptional cold hardiness and heat tolerance, hydrangea selections are a fit for many gardens. These low-maintenance growers perform best with appropriate light and water conditions. Choosing the right shrub for your USDA hardiness zone and meeting its essential cultural requirements are the first steps in finding the best and longest-lasting hydrangea for your garden.

Choosing the Right Hydrangeas

Commercial growers introduce new and dynamic cultivars each year to become beautiful garden additions. These newcomers, alongside favorite classic varieties, make choosing which hydrangeas to grow a happy challenge. 

One vital consideration in helping narrow the field is identifying cold hardiness in relation to your USDA growing zone. Gardeners in areas with cold winters need winter-hardy varieties, while warm-area gardeners have the luxury of numerous options but with added attention to garden placement in especially hot and humid spots. 

Microclimate considerations for your particular growing area are additional factors in hydrangea selections. Depending on the variety, they prefer certain light conditions. They’ll also benefit from regular moisture (the genus name is from the Greek “hydor,” or water). 

Some types tolerate more sun, with morning sun and afternoon shade offering ideal conditions for many varieties. Depending on the sun’s intensity, others grow best in partial to full shade and filtered light. Hydrangeas tolerate more sun in cool climates if there’s ample water. In hot climates, the same variety may grow best in partial shade with protection from direct sun – especially afternoon sun.

Old Wood Vs. New Wood

These plants bloom either on old wood (the previous year’s growth) or new wood (the current year’s growth). Some varieties – we’ll explore a few below  – bloom on both new and old wood for the best success of prolific flowering.

Knowing if a hydrangea blooms on old or new wood is important for growing hydrangeas in cold climates. Species that bloom solely on old wood set their buds in late summer for blooming the following year. In frigid winters, these old wood buds are susceptible to freezing and dropping, meaning there won’t be a showy bloom display come summer.

Types that bloom on new wood set their buds in the spring for summer blooming. This late set means buds don’t need to endure cold winter temperatures or risk freezing. They’ll emerge closer to bloom time.

It’s also helpful to know if your shrub is an old wood or new wood bloomer (or both) when it comes to pruning. An old wood hydrangea pruned in the fall means a lack of flowering the following year. A new wood hydrangea takes pruning in fall and late winter and still sets buds and blooms that summer.

Types of Hydrangeas 

While there are nearly 75 species of hydrangea, we commonly grow six in our gardens (and there are many cultivars to choose from). 

Panicle Hydrangea

Hydrangea paniculata, or peegee hydrangea, features showy pyramidal blooms tightly packed with individual flowers. Its colors range from creamy white to lime green to pink, tinged with red. Panicle hydrangeas bloom on new wood and are cold-hardy. They grow best in zones 3-8 (borderline in 9).

Panicles are adaptable hydrangeas that tolerate more sun than other varieties, even in warm climates. They adapt to varying soils and occasional dry spells, though consistent moisture is best for flowering. The large flower heads get weighty on the stem, but newer cultivars feature improved stem strength. The species’ height varies from 2 to 25 feet, depending on the variety.

Smooth Hydrangea

Hydrangea arborescens, also called wild hydrangea, is native to the United States and a great grower across varying climates in zones 3-9. Buds emerge on new wood for flowers in white, ivory, and pink, maturing to light green. Flowers appear in flat clusters from early summer through fall. Smooth hydrangeas grow three to five feet tall and prefer partial to full shade. Plants tolerate a variety of soil conditions but don’t withstand drought.

Bigleaf Hydrangea

Hydrangea macrophylla boasts the mophead and lacecap blooms we love. Large flowers in blues, pinks, and purples transition to pink and green. These prolific bloomers require regular moisture and afternoon sun protection. Bigleaf hydrangea is hardy to zones 6-11, with some cultivars down to zone 5. Old wood cultivars need winter protection in the lowest growing zones. Blooms emerge on old wood and old wood and new wood, depending on the variety. Plants reach three to six feet tall.

Mountain Hydrangea

Hydrangea serrata is similar in appearance to bigleaf hydrangea. It is cold-hardy but less robust than H. macrophylla, as expert plantsman Michael Dirr notes in his Hydrangeas for American Gardens. Mountain hydrangea is more compact (reaching two to four feet tall) with smaller lacecap flowers. 

Oakleaf

Hydrangea quercifolia is a North American native from the southeastern U.S. The upright shrubs bear lovely creamy white pyramidal blooms and deeply lobed leaves with red fall color. Cultivars feature improved forms and color variations like deep rose. Hardy in zones 5-9, oakleaf needs winter protection in zone 5. Plants bloom on old wood and reach four to eight feet tall.

Climbing Hydrangea

Hydrangea anomala subsp. petiolaris is a totally different form, with woody climbing vines that reach 30 to 40 feet high in optimal conditions. Large, flat-bloom clusters of fragrant white flowers emerge in late spring and early summer.

Climbing varieties are hardy in zones 4-9 (somewhat borderline in zones 4 and 9). Hot and humid southeastern summers can stress the climbers. The subspecies petiolaris is more cold-hardy than the straight species with larger blooms on old wood.

Cool Climate Zones

Hydrangeas span most growing zones, and strong selections abound for the cool climate garden. Paying attention to growing zones is especially important for frigid climates (and very hot ones, too) to ensure you’re getting the hardiest of the group. Hardy hydrangeas withstand winter extremes and freeze conditions.

In areas with extremely cold winters, opt for panicle and smooth hydrangeas. These bloom on new wood, so there won’t be winter bud damage, and they are exceptionally cold-hardy down to zone 3.

Cold Climate Growing Tips

Selections that bloom on old wood benefit from winter protection in cold regions for best flowering. To protect hydrangeas from winter extremes:

• Mulch generously around roots with pine bark, clean straw, or leaf litter
• Water regularly until the ground freezes (about 1” per week)
• Keep them out of drying winter winds or provide a windscreen
• In areas with temperatures consistently below 5°F (-15°C), wrap plants with burlap or plant bags or create a cage around plants to fill with leaf litter
• Move plants growing in containers to a sheltered space like a garage or basement for overwintering

Plants also need protection during hard frosts in late spring to preserve developing buds on new-wood bloomers.

Cold-Hardy Selections

There are many gorgeous selections for cool climates. Here are a mere few that bloom on new wood or old and new wood and are cold-hardy for gardens in zones 3 through 6. Gardeners in warmer zones also enjoy growing these beauties.

‘Limelight’

	botanical name Hydrangea paniculata ‘Limelight’
	sun requirements Full sun to partial shade
	height 6-8’
	hardiness zones 4-8

‘Limelight’ is a classic panicle variety that brings a big show to the mid-summer garden. Huge pyramidal blooms in creamy white and chartreuse age to shades of pink and dusky rose as summer approaches fall.

Plants are tall, statuesque, and exceptional as hedges, screens, or specimen plantings. ‘Limelight’ is an award-winning variety. It is a reliable bloomer and durable garden performer. It grows in full sun in cool climates and prefers afternoon shade in warm regions. Provide well-draining soils for plants to thrive.

‘Limelight Prime’ is a newer cultivar that offers improvements over the original. Flowers appear earlier in the season for a long-lasting bloom time.  Plants grow four to six feet tall with sturdier stems to hold the weighty blooms upright. Flowers emerge greenish-white and mature to rich pinks and reds for vibrant color.

For a more compact grower, opt for ‘Little Lime’. Robust blooms top strong stems that resist drooping. ‘Little Lime’ reaches three to five feet tall and has the same beautiful ‘Limelight’ green and ivory flowers that transition to pink hues and last well into fall.

‘Incrediball’

	botanical name Hydrangea arborescens ‘Incrediball’
	sun requirements Full sun to partial shade
	height 4-5’
	hardiness zones 3-8

This smooth hydrangea is a showstopper. Its giant snowball blooms in bright white transition to soft green. ‘Incrediball’ features strong stems that hold the hefty blooms aloft. 

For the most vigorous stems and flowering, grow ‘Incrediball’ in at least six hours of sunlight daily. In warm climates, allow more shade. Morning sun with afternoon shade or dappled light is ideal.

For a sweet addition in silvery pink, look for ‘Incrediball Blush’. Sturdy stems hold enormous blooms in delicate blush pink that mature to deep pink and green in the fall. ‘Incrediball Blush’ is a reblooming variety, producing flowers from early summer until frost.

‘Bloomstruck’

	botanical name Hydrangea macrophylla ‘PIIHM-II’ PP25,556
	sun requirements Partial shade to shade
	height 3-4’
	hardiness zones 4-9

‘Bloomstruck’ is part of the Endless SummerⓇ series, the first bigleaf hydrangeas to bloom on old and new wood. Large mophead blooms in blue (acidic soils) and violet pink (alkaline soils) grow among glossy green foliage.

These are exceptionally cold-hardy selections, bred from two strong parents in the series for their hardiness. ‘Bloomstruck’ withstands winters down to zone 4 and benefits from a thick layer of mulch of pine bark, compost, straw, or leaf litter. For added insulation at the plant’s base, pile straw or leaf litter up to 12 inches high around stems. Remove the material after the final frost in late winter or early spring. 

‘Bloomstruck’ is a repeat bloomer that begins blooming in late spring and early summer and continues throughout the warm season. This type prefers partial shade and dappled sunlight, though bigleaf varieties tolerate sunnier locations in cool climates with consistent soil moisture. True to their name, bigleaf hydrangeas need regular water to prevent wilting.

Warm Climate Zones

In moderate climates, there are options galore when it comes to hydrangeas. In particularly hot climates, look for the uppermost growing zones, generally zone 9, for the best selections. Hydrangeas may grow in zone 10, with special care given to light, water, and garden placement.

Warm Climate Growing Tips

In areas with warm summers, pay special attention to hydrangeas’ light and water requirements. For gardeners with hot summers, consider placing them on the shadier side of the preferred light requirements. Provide regular water, especially until established and during dry spells. With exposure to direct sun, water needs increase, particularly with bigleaf varieties.

Some types, like H. paniculata, tolerate more sun and periods of drought. However, during periods of stress, they’ll drop blooms and leaves. Here are a few care tips to protect these perennial shrubs during hot and dry spells:

• Water deeply at the heatwave’s onset to provide a moisture base
• Increase watering sessions; watering regularly and deeply rather than shallowly and frequently
• Avoid splashing foliage when possible to reduce fungal diseases
• Water in the morning (preferable) or evening for best moisture retention
• Provide extra shade with shade cloth, fabric, or umbrella coverage in sunny conditions
• Move potted plants to shady, protected garden areas

Heat-Tolerant Selections

With ample water and air circulation, hydrangeas thrive in warm climates. You’ll have the advantage of an array of varieties, including those that tolerate colder zones. Below are a few favorites for gardens in zones 7 through 9 (and cooler).

‘Big Daddy’

	botanical name Hydrangea macrophylla ‘Big Daddy’
	sun requirements Partial to full shade
	height 5-6’
	hardiness zones 6-9

‘Big Daddy’ celebrates hot and humid summers with stunning mophead blooms in blue or pink depending on soil acidity (blue) and alkalinity (pink). Glossy, large leaves complement the impressive blooms.

‘Big Daddy’ blooms on both old and new wood. This vigorous producer reblooms throughout summer until fall for a continual display.

Bigleafs appreciate partial shade, especially in the heat of the day, and ‘Big Daddy’ tolerates full shade in hot climates. This easy-care variety thrives in rich, medium-moist soils with good drainage.

‘Snow Queen’

	botanical name Hydrangea quercifolia ‘Flemygea’
	sun requirements Full sun to partial shade
	height 4-6’
	hardiness zones 5-9

‘Snow Queen’ is a stately oakleaf type with long pyramidal blooms (up to 12 inches!) of pure white flowers that take on pink and purple tones as the season progresses. Flowers emerge in spring and last into early summer. ‘Snow Queen’ resembles the straight species but with a tidier, rounded, upright habit, more prominent blooms, and sturdier stems.

Deeply lobed foliage turns vibrant red and burgundy in the fall. Oakleaf hydrangeas have exfoliating bark in coppery brown that adds winter interest.

Oakleafs are carefree growers with a naturalized aesthetic. Native to the southeastern U.S., they tolerate hot summer conditions. They thrive in moist, well-drained soils with mulch, compost, or leaves to aid in retaining moisture and regulating soil temperatures.

‘Mariesii Variegata’

	botanical name Hydrangea macrophylla ‘Mariesii Variegata’
	sun requirements Partial shade
	height 4-6’
	hardiness zones 6-9

This bigleaf hydrangea features unique foliage with pretty variegation and rich lacecap blooms. Its dark green leaves have creamy white margins, cooling the summer display. 

Flat, lacecap flower clusters have blue or pink centers with light florets. ‘Mariesii Variegata’ needs regular moisture and partial shade for best growth, especially in intense summer heat. Plants tolerate more shade in hot climates. 

Use this lovely variegated variety in small groupings for impact or as a specimen in mixed plantings. Grow them in a container to enjoy the foliage and flowers up close.