Blue Hydrangeas: 8 Stunning Varieties for Your Garden

Blue hydrangeas are a timeless favorite in the garden, known for their cool, calming hues and showy summer blooms. From sky blue to rich sapphire, their blue-colored flowers create a striking contrast against green foliage and brighten shady borders or foundation beds. Not all hydrangeas bloom blue, only certain varieties of bigleaf and mountain hydrangeas can shift in color depending on soil conditions.

Blue hydrangeas bring a sense of tranquility and sophistication to the garden. Their cool tones pair beautifully with silver foliage, white flowers, and soft pastels, making them a favorite for cottage borders, coastal landscapes, and shaded retreats.

On this page: Varieties | Why Are Some Hydrangeas Blue? | Design Ideas

On this page:

BLUE HYDRANGEA VARIETIES
WHY ARE SOME HYDRANGEAS BLUE?
DESIGN IDEAS WITH BLUE HYDRANGEAS

BLUE HYDRANGEA VARIETIES

Photo by: Proven Winners.

LET'S DANCE SKY VIEW® — Buy now from Proven Winners
Hydrangea macrophylla x serrata

Zones: 4-9
Height/Spread: 2 to 3 feet tall, 2 to 4 feet wide
Bloom time: Summer through fall
Flower color: Blue, pink, or purple

This compact rebloomer stands out with abundant sky-blue blooms and a fresh green eye. Cold-hardy, heat-tolerant, and easy to grow, it flowers on both old and new wood—ideal for garden beds or containers.

See what makes this hydrangea so special in the video, A Reblooming Hydrangea with Stunning Color, with Stacey Hirvela from Proven Winners ColorChoice Shrubs.

Photo by: Proven Winners.

LET'S DANCE LOVABLE® — Buy now from Proven Winners
Hydrangea macrophylla

Zones: 5-9
Height/Spread: 3 to 4 feet tall and wide
Bloom time: Summer
Flower color: Blue, purple, or pink

True to its name, this reliable rebloomer is packed with vibrant color and charm. It produces a profusion of bold blooms on both old and new wood for nonstop summer beauty.

Photo by: Proven Winners.

LET'S DANCE RHYTHMIC BLUE® — Buy now from Proven Winners
Hydrangea macrophylla

Zones: 5-9
Height/Spread: 3 to 4 feet tall and wide
Bloom time: Mid-summer through early fall
Flower color: Blue or pink

Developed for cold climates, this hardy rebloomer delivers months of full, richly colored mophead blooms. Its uniquely shaped florets create a lush, polished look with no pruning needed.

Photo by: Proven Winners.

LET'S DANCE BLUE JANGLES® — Buy now from Proven Winners
Hydrangea macrophylla

Zones: 5-9
Height/Spread: 1 to 2 feet tall, 2 to 3 feet wide
Bloom time: Summer
Flower color: Blue, purple, or pink

This compact reblooming hydrangea delivers large, intense mophead blooms on a tidy, well-branched plant. Its low, rounded shape makes it ideal for borders, small gardens, and containers, with reliable color and flower power all summer long.

Photo by: Proven Winners.

TUFF STUFF AH-HA® — Buy now from Proven Winners
Hydrangea serrata

Zones: 5-9
Height/Spread: 2 to 3 feet tall and wide
Bloom time: Summer through fall
Flower color: Blue or pink

A nonstop bloomer with distinctive double florets that resemble waterlilies. This compact, cold-hardy mountain hydrangea produces a steady supply of colorful blooms from early summer through frost.

Photo by: Proven Winners.

TINY TUFF STUFF™ — Buy now from Proven Winners
(Hydrangea serrata)

Zones: 4-9
Height/Spread: 18 to 24 inches tall and wide
Bloom time: Summer
Flower color: Blue or pink

Don’t let the delicate look fool you—this compact reblooming mountain hydrangea is tough, reliable, and incredibly cold-hardy. Its dainty lacecap blooms, often double-sepaled, cover the plant each summer and age gracefully to soft pink. Perfect for small spaces and refined garden designs.

Photo by: ANGHI / Shutterstock.

'NIKKO BLUE'
Hydrangea macrophylla)

Zones: 5-9
Height/Spread: 4 to 6 feet tall and wide
Bloom time: Early summer
Color: Blue or pink

A beloved heirloom bigleaf hydrangea known for its large, rounded clusters of vivid blue blooms. With a graceful, mounding habit and glossy green foliage, it adds a timeless touch to borders, foundation plantings, and cottage gardens. Blooms on old wood in early to mid-summer.

Photo by: Ellen McKnight / Shutterstock.

ENDLESS SUMMER®
Hydrangea macrophylla 'Balimer')

Zones: 4-9
Height/Spread: 6 to 8 feet tall and wide
Bloom time: Late spring to fall
Color: Blue or pink

The original reblooming bigleaf hydrangea that changed the game, producing large, showy mophead blooms on both old and new wood. Its rounded habit and dependable flowering make it a favorite for long-lasting color in borders, beds, and containers.

WHY ARE SOME HYDRANGEAS BLUE?

The blue flower color in hydrangeas isn’t just about genetics, it’s also about soil pH and the availability of aluminum. Certain varieties of bigleaf (H. macrophylla) and mountain (H. serrata) can produce blue blooms when grown in acidic soil, while those same plants may turn pink or purple in more alkaline conditions.

Not all hydrangeas have this ability. As Proven Winners notes, "Smooth and panicle hydrangeas undergo some color change as they age, but their flowers cannot be turned blue."

Learn how to adjust your soil to influence bloom color: Changing Hydrangea Color.

DESIGN IDEAS WITH BLUE HYDRANGEAS

Blue hydrangeas are as versatile as they are beautiful. The beautiful blue tones bring a sense of calm and elegance to the garden and pair effortlessly with a variety of styles:

Cottage gardens: Mix with roses, delphiniums, and foxgloves for a soft, romantic look.
Coastal or seaside gardens: Combine with ornamental grasses, white flowers, and weathered wood elements.
Shade gardens: Brighten darker areas by planting with ferns, hostas, and variegated foliage.
Modern spaces: Use mass plantings of one variety for bold impact, especially with clean lines and contrasting textures.