Not a common color among flowering plants, blue adds a unique beauty to the garden. Its calming hue invites wanderers to pause and take notice. Bring some cooler hues to your landscape this year with beautiful annual blue flowers.
1. Bachelor’s buttons (Centaurea cyanus)
Also called cornflower, bachelor’s buttons can often be seen blooming along roadsides in summer. Its beautiful blue flower heads provide nectar for butterflies and make for an attractive, long-lasting cut flower. Deadhead to reduce reseeding, but leave some seed heads to attract birds.
This highly adaptable plant tolerates poor soils and dry conditions but appreciates moist, well-drained soil in full sun.
2. Love-in-a-mist (Nigella damascena)
Named for the delicate, “misty” bracts surrounding each flower, love-in-a-mist produces unique blue blooms with pronounced stamens that bring beauty to the garden as well as fresh arrangements. The attractive seed pods, too, work well in dried bouquets.
Love-in-a-mist grows best in average, moist, well-drained soil in full sun.
3. Salvia (Salvia spp.)
While many salvias come in shades of red or purple, a few, such as sky-blue sage (S. uliginosa) and arrowleaf sage (S. sagittata) have lovely blue blossoms. These tubular flowers bloom on upright spikes and attract hummingbirds, butterflies, bees, and other pollinators.
Salvias typically perform well in moist, organically rich soil with good drainage in full to part sun. Sky-blue sage, also called bog sage, tolerates poorly drained soil and actually prefers damp conditions.
4. Dwarf morning glory (Evolvulus glomeratus)
A trailing rather than climbing plant, dwarf morning glory forms a carpet of small, fuzzy, oval leaves that will also cascade when planted in hanging baskets or other containers. The brilliant blue flowers have white centers and bloom from early summer until frost.
Though a perennial in warmer regions, dwarf morning glory is not hardy and is often grown as an annual. It appreciates full sun and good drainage and will tolerate drought.
5. Lobelia (Lobelia erinus)
The many cultivars of lobelia provide a range of blue flowers, from the clear, soft blue of ‘Cambridge Blue’ to the dark blue of ‘Blue Moon’. They also come in small, compact forms and trailing habits. If cut back, the tubular, five-parted flowers will bloom multiple times.
Lobelia requires full to part sun and moist soil with good drainage.
6. Swan river daisy (Brachyscome iberidifolia)
Swan river daisy blooms profusely throughout the summer, its inch-wide flowers featuring a yellow or black center surrounded by blue petals (also available in white, pink, or purple). The fine foliage has a mounded habit, and the plant averages 12 to 18 inches tall and wide.
This easygoing plant thrives in full sun and well-drained soil. Though commonly grown as an annual in most of the US, it may overwinter in USDA zones 9-11.
7. Larkspur (Delphinium spp.)
From midspring to midsummer, larkspur produces spikes of white to blue flowers that each have a single spur on the back. The leaves are palmately divided or lobed and may be fine and feathery, depending on the species or cultivar, of which there are many.
This woodland wildflower prefers moist, fertile, well-drained soil in full sun, with some afternoon shade in hot summers. Deadheading encourages a second, late-season flush of blooms.
8. Bush violet (Browallia viscosa)
With flowers in shades of blue with white centers, bush violet grows in a bushy mound eight inches to two feet tall. The ovate leaves nicely complement the summer flowers, which attract hummingbirds. This plant is especially lovely in pots or haning baskets.
Bush violet appreciates full sun with afternoon shade and rich, moist, well-drained soil.
9. Cineraria (Pericallis x hybrida)
The daisy-like blooms of cineraria come in a range of bright colors, including blue, and often have a striking white ring around the center. They bloom winter to spring and are often grown as house plants as well as outdoor annuals.
Cineraria likes moist, fertile soil with good drainage in partial shade.
10. Amazon blue (Achetaria azurea)
Sometimes called Brazilian snapdragon, Amazon blue has blue, two-petaled flowers that resemble snapdragons. Each of the lower petals has a white streak toward the base. In most parts of the US, where it’s grown as an annual, it blooms midsummer into fall.
Amazon blue prefers full sun to part shade and moist, well-drained soil. It will bloom almost year-round in zones 9-11 or when grown as a house plant.
11. Floss flower (Ageratum houstonianum)
Floss flower forms six-inch to foot-tall mounds of ovate to deltoid foliage and bloom all season long. The fluffy, aster-like flowers bloom in clusters and retain their color for a long time, making the taller varieties good cut flowers.
Though somewhat drought tolerant, floss flower appreciates rich, moist soil with good drainage in full sun.
