Growing Green: True Blue Gradening
I’m sure you’ve heard me say it before, I LOVE BLUE IN THE GARDEN. True blue plants are hard to come by. Most plants described as blue are actually shades of purple from eggplant to lilac. Because it is so hard to find, blue can be used to create a different and unusual effect in your garden. Blue colors are cool, and a garden filled with a variety of blue plants will be a welcome place to relax during hot summer days. If you would like to include “the blues” in your garden this year, try out some of these plants.
Centaurea cyanus (Cornflower) - This charming sun loving annual has vivid blue flowers that bloom in late spring-early summer. Its tall wiry stems and long lasting ruffled blossoms make it a good choice for cutting. Its flowers attract bees and butterflies too. Height: 30". Spread: 12".
Brunnera Macrophylla (Siberian Bugloss) –This shade loving perennial (hardy to zone 3) grows 12 to 15 inches tall and will spread to about 20 inches wide. ‘Jack Frost' is one of the most popular varieties. The heart-shaped leaves are a frosty silver color with light green veins. Bright blue flower clusters appear in mid-late spring.
Nigella damascene: Love-in-a-mist is a hardy annual with fine, feathery foliage and 1 ½” blue flowers. An excellent cut flower it also forms interesting horned seed pods, which are striking in dried arrangements. Prefers cool weather. Grows 1.5 feet tall.
Campanula carpatica ‘Blue Clips’ is one of the most popular bellflowers. Hardy to zone 3, this perennial plant creates a low carpet of attractive leaves topped with upward facing flowers from June thru October. Its compact, rounded form (12” high, 10” wide) makes it an ideal choice for an edging plant or in a rock garden. It will grow in full sun to partial shade and is rabbit resistant.
Delphinium grandiflorum - Delphiniums offer some of the truest-blue flowers in the garden. These perennials are hardy to zone 3and bloom all summer long. They are very tall, (up to 6’) with a spread of 12” (Staking is advised to protect these plants for stormy weather.) Delphinium prefers moist, rich soil and full sun. They make exceptional cut flowers and will attract hummingbirds.
Eryngium planum ‘Blue Glitter’: Sea Holly is an herbaceous perennial with stiff grey-blue leaves and thistle-like steel-blue flowers in summer. It is tolerant of hot, dry sites, and soils high in salts. It prefers full sun, and flowers all summer long. An excellent dried flower, pick stems just as the flower clusters open fully, and hang upside down to dry in a warm, dark place. Attracts butterflies.
Let me know if you try the blues in your garden this year. If you would like to learn about a specific flower this spring, contact me at the University of Minnesota Extension Office, Douglas County at 320-762-3890.
Robin Trott is a Horticulture Educator with University of Minnesota Extension.