18 of the Most Stunning Blue Flowers You'll Love Growing in Your Garden

A big, sky blue hydrangea flower is absolutely breathtaking. Get your bigleaf hydrangeas to turn clear, sky blue by increasing the acidity of the soil. Adding soil sulfur is one way to do this. Bigleaf hydrangeas typically flower on last-year's growth, so if you need to prune them, do so right after they finish flowering. And look for newer varieties such as Endless Summer, which produce flowers on both new and old growth.

Name: Hydrangea macrophylla selections

Growing Conditions: Morning sun and afternoon shade in moist, well-drained soil that's rich in organic matter. Don't let bigleaf hydrangeas get too dry.

Size: To 7 feet tall and wide, depending on variety

Zones: 4-9, depending on the variety

Plant it with: Blue bigleaf hydrangeas look stunning when paired with white-flowering varieties such as 'Annabelle' hydrangea or oakleaf hydrangea.

Buy It: Let's Dance Rhythmic Blue Hydrangea ($37, The Home Depot)

There are plenty of perennials that offer blue flowers, but 'Rozanne' perennial geranium is one of the best. This long-blooming plant flowers from June to frost, producing a nearly endless supply of violet-blue flowers.

Plant Name: Geranium 'Rozanne'

Growing Conditions: Full sun to part shade in moist, well-drained soil

Size: To 2 feet tall and 3 feet wide

Zones: 4-8

Plant it with: Because the geranium starts flowering in early summer, pair it with spring-blooming bulbs such as grape hyacinth, crocus, and white daffodils to add color before this perennial gets going.

Buy It: Rozanne Everblooming Geranium ($22, Breck's)

Delphiniums offer some of the truest-blue flowers in the garden. Though perennial, these plants tend to be short-lived and don't do well in heat and humidity so sometimes they are treated like annuals. Stake taller delphinium varieties to keep their flower spikes from toppling over in the wind. Grow them in soil that's rich in organic matter and provide a balanced fertilizer to encourage the best blue blooms.

Plant Name: Delphinium selections

Growing Conditions: Full sun to part shade and moist, well-drained soil

Size: To 6 feet tall and 1 foot wide, depending on type

Zones: 3-7, depending on type

Plant it with: Blue-flowering dwarf delphiniums such as 'Butterfly Blue' or 'Summer Nights' look fantastic with the yellow blooms of Coreopsis 'Moonbeam' or 'Fanfare' blanket flower.

A gorgeous but underused shade plant, brunnera (which also goes by the common name Siberian bugloss) produces sprays of tiny, pale blue, spring flowers that resemble forget-me-nots. Add to the color show by choosing a variegated selection, such as 'Jack Frost', 'Silver Heart', or 'King's Ransom' (shown here), which have silver splashed leaves.

Plant Name: Brunnera macrophylla

Growing Conditions: Shade and moist, well-drained soil

Size: To 2 feet tall and wide

Zones: 3-7

Plant it with: The springtime flowers look fantastic paired with white or yellow daffodils or with silvery Japanese painted fern.

Buy It: Silver Heart Siberian Bugloss ($21, Breck's)

A small but beautiful spring-flowering bulb, grape hyacinth produces clusters of blue flowers in midspring. You can also find varieties that bear purple, white, or yellow flowers, too.

Plant Name: Muscari

Growing Conditions: Sun or shade in well-drained soil

Size: To 8 inches tall and 3 inches wide

Zones: 4-8

Plant it with: Yellow daffodils are a classic choice, but you can extend the season by planting them with late-spring-blooming perennials such as columbine that keep the color show going after grape hyacinth has faded.

Buy It: Blue Grape Hyacinth ($10, Breck's)

Blooming in a range of colors, clematis is a beautiful vine to add to your garden. The true blue-flowering varieties include 'Crystal Fountain', 'Ice Blue', or 'Arabella'. Give these vines a trellis or other support to climb.

Plant Name: Clematis selections

Growing Conditions: Full sun and moist, well-drained soil

Size: Most clematis climb to about 12 feet, but some can reach more than 25 feet.

Zones: 3-9, depending on type

Plant it with: A classic way to grow clematis is to combine them with climbing roses. Create contrast by planting a blue-flowering clematis with yellow rose such as 'Graham Thomas Climbing' or a white type such as 'Climbing Iceberg'.

As you might guess, bluestar features starry blue flowers that appear in late spring. This native plant is also heat, drought, deer, and rabbit resistant. Plus, the foliage turns a beautiful shade of yellow at the end of the season.

Plant Name: Amsonia tabernaemontana

Growing Conditions: Full sun or part shade and well-drained soil

Size: To 2 feet tall and wide

Zones: 3-9

Plant it with: Columbines are perfect companions for bluestar. Create a harmonious color scheme by planting blue- or white-flowering columbines; create contrast with yellow varieties.

Buy It: Blue Ice Amsonia ($15, Breck's)

Also called hardy plumbago, leadwort is a vigorous perennial groundcover. It puts on a show at the end of the season with its sky blue flowers and rich red fall foliage. This plant grows more slowly in shade, but still blooms well.

Plant Name: Ceratostigma plumbaginoides

Growing Conditions: Sun or shade and well-drained soil

Size: To 1 foot tall and 2 feet wide

Zones: 5-9

Plant it with: Create a bold, end-of-the-season display by pairing lead plant with yellow chrysanthemums or white asters.

Often used in cottage gardens, bellflowers produce starry or bell-shape flowers in blue, violet, pink, or white. Many of the longer-stemmed varieties make excellent cut flowers. Dwarf types, such as 'Pearl Deep Blue' work well as groundcovers.

Plant Name: Campanula selections

Growing Conditions: Full sun or part shade and moist, well-drained soil

Size: To 3 feet tall and 2 feet wide, depending on type

Zones: 3-9, depending on type

Plant it with: Bellflowers are prefect companions for blue pincushion flowers (Scabiosa). Bonus: Both are great for cutting!

Buy It: Campanula Carpatica Blue Clips Bellflower ($10, Etsy)

Both annual and perennial salvia varieties have become garden champions for their heat and drought tolerance, as well as the fact that deer and bunnies tend to leave them alone. For true blue flowers, look for Salvia azurea or S. patens (shown here). Other varieties of salvia, such as 'May Night' or 'Blue Mound', offer more violet blue flowers.

Plant Name: Salvia selections

Growing Conditions: Full sun and well-drained soil

Size: To 5 feet tall and wide, depending on type

Zones: 3-9, depending on type

Plant it with: Blue salvia look wonderful with penstemon, a native perennial which is also heat and drought resistant.

Buy It: Blue Hill Salvia ($40, Breck's)

An easy-to-grow perennial, balloon flower offers puffy, round buds that open to beautiful blue, pink, or white star-shape blooms for several weeks in summer.

Plant Name: Platycodon grandiflorus

Growing Conditions: Full sun and well-drained soil

Size: To 2 feet tall and 1 foot wide

Zones: 4-9

Plant it with: The lilac-pink flowers of 'Appleblossom' yarrow (Achillea) or gaura are a perfect complement to blue balloon flowers.

Buy It: Blue Balloon Flower ($23, Breck's)

One of the last plants to bloom in many gardens, asters light up the fall landscape and draw pollinators with their starry flowers. These perennials also make long-lasting cut flowers.

Plant Name: Symphyotrichum selections

Growing Conditions: Full sun and well-drained soil

Size: To 5 feet tall and 3 feet wide

Zones: 3-9, depending on type

Plant it with: Goldenrod and mums are two perfect partners for blue asters.

Buy It: Marie Ballard Aster ($15, Breck's)

Loved by generations of gardeners, morning glory vines come in varieties that offer saucer-shape sky blue flowers. Other varieties bear blooms in bright pink, bold red, purple, white, and even bicolors such as the blue-and-white 'Flying Saucers' variety shown here. This vigorous annual vine is easy to grow from seed and can self-seed prolifically in situations where it's happy.

Plant Name: Ipomoea tricolor

Growing Conditions: Full sun and well-drained soil

Size: Climbs to 12 feet tall or more

Zones: Annual

Buy It: Flying Saucer Morning Glory Vine Seeds ($4, Etsy)

A pretty choice for shady gardens, Siberian squill makes a tiny but eye-catching display of bright blue flowers in early spring. Plus, these small bulbs will naturalize over time, meaning they will slowly spread to create a beautiful blooming carpet.

Plant Name: Scilla siberica

Growing Conditions: Full sun to part shade and well-drained soil

Size: 4-6 inches tall

Zones: 2-8

Plant it with: contrast blue scilla with pink, yellow, or orange early-flowering species tulips. It also mixes well with other small early bulbs such as snowdrops.

Buy It: Scilla siberica 'Spring Beauty' bulbs (from $5, Etsy)

This annual gets its colorful name from the ferny green leaves that set off the flowers. Love-in-a-mist is easy to grow from seed, and will reseed itself around the garden so you don't have to keep replanting it. Even after the striking blue petals are gone, the large round seedpods add interest to the garden and vase.

Plant Name: Nigella damascena

Growing Conditions: Full sun to part shade and well-drained soil

Size: up to 2 feet tall

Zones: annual

Plant it with: try love-in-a-mist with other colorful annuals with contrasting flower shapes such as celosia and globe amaranth.

Buy It: Jewels Indigo Nigella seeds ($3, Etsy)

The tall blue flower spires of baptisia always make an impressive display, starting in spring and going into summer. The large dark seedpods that follow also look interesting. Also known as false indigo, this bold native perennial is easy to grow because it can tolerant heat and drought well, and deer and other pests don't bother it.

Plant Name: Baptisia australis

Growing Conditions: Full sun and well-drained soil

Size: 4 feet tall

Zones: 3-8

Plant it with: for a prairie effect, plant baptisia with other natives such as purple coneflower, milkweed, and switchgrass.

With myriad types to choose from, irises come in every shade except black. For the best blue-flowered irises, look for bearded iris, Siberian iris, reticulated iris, and Japanese iris (shown here) varieties.

Plant Name: Iris

Growing Conditions: Full sun and well-drained soil

Size: 6 inches to 3 feet tall, depending on variety

Zones: 4-9

Buy It: Forever Blue Dwarf Reblooming Bearded Iris($30, Breck's)

The coarsely textured leaves and name of globe thistle may make you think of its weedier relatives, but this pretty perennial will make a well-behaved addition to your garden. Its long-lasting, steel blue, spherical blooms appear in summer, and make good cut flowers.

Plant Name: Echinops ritro

Growing Conditions: Full sun and well-drained soil

Size: 1-3 feet tall

Zones: 3-9

Buy It: Globe Thistle Seeds ($11, Etsy)