10 Blue and Lavender Flowering Shrub Ideas

Azaleas Are Only the Beginning

Lavender plant with purple flowers closeup

The Spruce / Evgeniya Vlasova

Shrubs with blue or lavender flowers are among the most treasured bushes in the landscape. Blue and lavender (and similar shades associated with purple, such as lilac) are considered "cool" colors in color theory, and their calming appearance makes a great addition to many gardens. These blue and purple beauties come in evergreen and deciduous varieties, which means some may lose their leaves during winter while others may not.

These flowering bushes are highly sought after for meditation gardens, but even casual gardeners can appreciate these plants. Blue and purple hues are highly favored blooms; hybrids in these colors continue to be developed.

Here, learn about the top 10 most beautiful flowers and shrubs that bloom in blue and lavender colors.

Tip

Pink hydrangea shrubs, particularly Hydrangea macrophylla, will turn blue if you make the soil more acidic. A 6.0 pH or lower produces blue flowers, while a pH of 7.0 or higher produces pink blooms. To acidify your soil, mix 1/4 oz. of aluminum sulfate in a gallon of water and apply it to the shrub's soil in the spring; reapply every month through the growing season.

  • 01 of 10

    Blue Butterfly Bush (Buddleia davidii)

    Monarch butterfly on blue Buddleia shrub.
    The Adonis Blue cultivar of butterfly bush is a true blue. Ed Reschke/Getty Images

    A few cultivars of butterfly bush (Buddleia davidii) have true blue flowers, such as 'Adonis Blue.' Others have misleading names, like 'Blue Heaven' and 'Blue Chip,' which are more of a lavender color than a true blue. The beauty of 'Blue Chip,' beyond its color, is that it is non-invasive.

    Butterfly bush originally came to the U.S. around 1900 and is considered a weed or invasive plant in at least 20 states. Although it attracts butterflies and other pollinators, it is only a host plant for non-native North American butterflies and caterpillars, crowding out native host plants.

    It grows best in USDA hardiness zones 5 to 9. It grows well, not requiring much maintenance beyond controlling its overgrowth. If not planted in full sun, it can get weedy and sparse. Some experts recommend cutting the plant down to ground level yearly to keep it under control.

    This cultivar typically grows to 6 to 12 feet, but heights of 15 feet are possible. It has a long flowering period, from June into early fall. 

    • Native Area: Asia
    • USDA Hardiness Zones: 5 to 9
    • Height: 6–15 ft. tall
    • Sun Exposure: Full
  • 02 of 10

    Blue Rose of Sharon (Hibiscus syriacus)

    Blue buds of Blue Bird rose of Sharon shrub.
    Hibiscus syriacus Blue Bird has deep-blue flower buds. Paul Seheult/Getty Images

    Several types of rose of Sharon (Hibiscus syriacus) sport genuinely showy blue flowers, including the 'Blue Bird' cultivar. Some names are deceiving, like 'Blue Chiffon,' which is not reliably true blue. It's more reliably lavender, like the late-summer flowering shrub, 'Lavender Chiffon.'

    Rose of Sharon originally comes from eastern Asia, spanning China to India. You can plant it in the spring or fall. It blooms from summer well into fall in most regions. It attracts bees, butterflies, hummingbirds, and other pollinators. This shrub can tolerate various growing conditions, not needing much maintenance. Prune it to keep its shape and limit its spread.

    • Native Area: Asia
    • USDA Hardiness Zones: 5 to 8
    • Height: 8–12 ft. tall
    • Sun Exposure: Full, partial
  • 03 of 10

    California Lilac (Ceanothus 'Concha')

    Ceanothus shrubs in bloom growing behind grasses.
    Matt Anker/Getty Images

    A blue flowering shrub from California aptly named California lilac (Ceanothus Concha) is not very cold-hardy, being suited only to zones 7 to 10. Where temperatures dip to 0 degrees Fahrenheit or lower, it will die back to the ground, although it often returns. 

    This plant is easy to grow and sends down deep roots, giving it good resistance to drought. It is a broadleaf evergreen best planted in the spring that will reach a mature height of 4 to 8 feet, with a spread of 6 to 12 feet.

    This June bloomer likes full sun and well-drained soil. It has purple or blue flowers, and the flowers are fragrant. You can train this plant's vibrant blooming branches to climb walls, fences, and door arches. Deer-resistant and drought-tolerant California lilac will draw hummingbirds and butterflies to the yard.

    • Native Area: North America
    • USDA Hardiness Zones: 7 to 10
    • Height: 2-20 ft. tall
    • Sun Exposure: Full, partial
  • 04 of 10

    Bluebeard (Caryopteris x Clandonensis)

    Blue beard shrub

    The Spruce / Evgeniya Vlasova

    Blue beard or blue mist shrub is a hybrid or a cross between Caryopteris and Clandonensis. Blue beard is a durable, easy-care plant usually planted in spring or fall that produces small, genuinely blue flowers. The roots are hardy to zone 5, but the top growth will die back in climates colder than zone 7.

    Several named cultivars are available, such as 'Blue Mist', 'Arthur Simmonds', 'Dark Knight', and 'Heavenly Blue'. These are nicely compact shrubs, most remaining under 3 feet in height. They usually bloom from July to September. This plant is excellent for succession planting since it blooms in late summer, long after many other flowering shrubs,

    • Native Area: Hybrid; parent plants are native to Asia
    • USDA Hardiness Zones: 7 to 9
    • Height: 2–4 ft. tall
    • Sun Exposure: Full
    Continue to 5 of 10 below.
  • 05 of 10

    Rhododendrons (Rhododendron spp.)

    Rhododendron 'Goteborg' with pink flowers and spotted centers

    The Spruce / Evgeniya Vlasova

    Rhododendrons and azaleas are in the same family—both come in deciduous and evergreen varieties. Most native species come from east Asia and the Himalayan region, but they also hail from North America and Europe. Rhododendron cultivars with blue or lavender flowers are widely grown; popular varieties include:

    • Catawpa rhododendron (Rhododendron catawbiense): Lavender-pink flowers from April to early June; hardy in zones 4 to 8
    • PJM rhododendron (Rhododendron (PJM group): Lavender-pink flowers in April; hardy in zones 4 to 8
    • 'Bob's Blue' (Rhododendron 'Bob's Blue'): True blue flowers in spring; hardy in zones 7 to 9
    • 'Blue Diamond' (Rhododendron 'Blue Diamond'); Blue-lavender flowers in spring and early summer; a dwarfish plant that is hardy in zones 7 to 9

    Its flower colors can be a more true blue shade than azaleas. Rhododendrons are larger shrubs with sizable leaves. The leaves are more leathery in texture and may be evergreen in a suitable climate. Rhododendron nectar is toxic to most animals, including some pollinators. Bees are the primary pollinators of rhododendrons.

    • Native Area: Asia, North America, Europe
    • USDA Hardiness Zones: 4 to 9
    • Height: 5-20 ft. tall
    • Sun Exposure: Full, partial
  • 06 of 10

    Azaleas (Rhododendron spp.)

    Lavender-colored azaleas against a mountain backdrop.
    Sang Ho Lee/Getty Images

    Azaleas (Rhododendron spp.) are easy to grow if you plant them in the right spot during spring or early fall; otherwise, they can be temperamental. Most evergreen azaleas come from Asia, while deciduous azaleas are native to North America and Europe. These plants come in various colors, including red, yellow, orange, and white. Lavender is one of the most popular colors, including:

    • 'Purple Gem,' hardy in zones 4 to 8; purple flowers
    • 'Conlee,' hardy in zones 6 to 10; purple flowers
    • 'Robles,' hardy in zones 6 to 10; purple flowers on a dwarf (less than 3 feet) shrub
    • 'Bloom-A-Thon Lavender,' a 3- to 4-foot tall plant with lavender flowers that may rebloom in fall; hardy in zones 6 to 9.

    Bees are most attracted to violet and blue azaleas (blue is very rare); azalea nectar is toxic to most animals, including bees. Regional arboretums have developed wide cold-hardy varieties that survive nicely up to zone 3. 

    • Native Area: Asia, Europe, North America
    • USDA Hardiness Zones: 3 to 10
    • Height: 3–20 ft. tall
    • Sun Exposure: Partial (Full in colder zones)
  • 07 of 10

    Russian Sage (Salvia yangii)

    Russian sage in bloom against an adobe wall.
    cstar55/Getty Images

    Russian sage (Salvia yangii, formerly Perovskia atriplicifolia) gives you an airy look in a flower border because its numerous, purplish-blue-colored flowers are tiny, and its small leaves have a silvery color. Flowers appear in mid-summer through fall, attracting honey bees, small carpenter bees, leafcutting bees, and hummingbirds. Its airy quality makes it a good filler plant. Grow it between plants that bear larger, showier flowers.  

    Although it has "Russian" in its name, it's native to central Asia in the region of Afghanistan. Hardy in zones 4 to 9, Russian sage is a sprawling 3- to 5-foot-tall plant. It grows easily in any soil and is drought tolerant.

    • Native Area: Asia
    • USDA Hardiness Zones: 3 to 9
    • Height: 3-5 ft. tall
    • Sun Exposure: Full
  • 08 of 10

    Lavender (Lavendula spp.)

    Row of lavender with purple flowers in a garden

    The Spruce / Evgeniya Vlasova

    No list of choices for shrubs with lavender-colored flowers would be complete without mentioning the color's namesake—lavender (Lavandula spp.). English lavender (L. angustifolia) is the most popular species because of its cold-hardiness (zones 5 to 8). Other varieties include:

    • French lavender (L. stoechas)
    • Portuguese (or "broadleaved") lavender (L. latifolia)
    • Fringed lavender (L. dentata)

    It is best known for its fragrant leaves and tiny purple blossoms. Besides its beauty and usefulness in the kitchen and potpourri, this early-summer bloomer is deer-resistant and drought-tolerant. It's so easy to care for that it tolerates a little bit of neglect without a problem. Although it's a bee magnet, it always has their attention. Plant it in the spring.

    • Native Area: Europe, Africa, Asia
    • USDA Hardiness Zones: 5 to 9
    • Height: 2–3 ft. tall
    • Sun Exposure: Full
    Continue to 9 of 10 below.
  • 09 of 10

    Common Lilac (Syringa vulgaris)

    Lilac bush blooming with lilac-colored flowers.
    Antema/Getty Images

    Common lilac bush (Syringa vulgaris)​ comes in several colors, including lavender-blue, white, burgundy, and deep purple. A top landscape shrub for generations, it is most valued for the sweet smell of its flowers. It originated in eastern Europe and Asia. Lilac varieties suit most climate regions, from zones 3 to 8. The best time to plant is late fall, before the ground freezes.

    This large shrub grows as tall as 20 feet, although some cultivars stop at 12 feet. Other lilac species are more compact, such as 'Miss Kim' (Syringa pubescens subsp. patula 'Miss Kim'), which remains under 9 feet; and dwarf Korean lilacs, such Syringa meyeri 'Palibin', which remains under 5 feet in height. Lilac shrubs are well-loved by pollinators.

    Lilacs are easy to care for and can adapt to most soils but can't tolerate poor drainage or high, prolonged heat. One of its few drawbacks is that its leaves tend to get powdery mildew by late summer. The mildew does not harm the plant, so you will be happy growing this late-spring bloomer if you can ignore it. 

    • Native Area: Europe and Asia
    • USDA Hardiness Zones: 3 to 7
    • Height: 8–15 ft. tall
    • Sun Exposure: Full
  • 10 of 10

    Heath and Heather (Erica spp. and Calluna spp.)

    Heather in mixed colors surrounding a golden fern.
    Guy Edwardes/Getty Images

    Heath and heather, although different plants, share many characteristics beyond having similar names. Heath belongs to the Erica genus, while heather belongs to the Calluna genus. They are from the Ericaceae family of plants and have a similar appearance and cultural needs in the landscape. Both are short shrubs, about 1 to 2 feet tall, with a spread of 2 to 3 feet. They grow easily in poor soils or acidic environments with good drainage.

    Heather and heath species live in zones 4 to 7. They are evergreen shrubs, best planted in spring. They bloom in spring, late summer, and fall, depending on the species and variety. Heath and heather are popular plants that attract pollinators of all kinds.

    Winter heath (Erica x darleyensis) is popular in North America—blooming from January through March. It is hardy in zones 5 to 7 and rarely grows above 1 foot tall.

    • Native Area: Europe, Asia
    • USDA Hardiness Zones: 4 to 7
    • Height: 1 ft. tall
    • Sun Exposure: Full, partial

You can find a blue or purple flowering shrub that will flower in most seasons, including winter. If blue is the color for you, stagger your plantings for a flash of blue-purple in your garden all year long.

Article Sources
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  1. Butterfly bush. University of Maryland Extension.

  2. Bee Health. National Cooperative Extension. U.S. Department of Agriculture.

  3. Selecting and growing azaleas. University of Georgia Extension.

  4. Russian sage, Perovskia atriplicifolia. Division of Extension. University of Wisconsin-Madison.

  5. Extension Web Support. “Herbs to the Rescue: Fend off Deer with Aromatic Plants.” Oregonstate.edu. N.p., 31 Mar. 2011. Web

  6. Lilacs: Read More. Arnold Arboretum. Harvard University.

  7. Growing lilacs. Cornell Cooperative Extension.

  8. Trees and shrubs for pollinators. University of Minnesota Extension.

  9. Pennsylvania State University Extension Office. “Powdery Mildew.” Psu.edu. N.p., n.d. Web.

  10. Lilac. Nebraska Extension Acreage Team. University of Nebraska-Lincoln.