How to Add this Much-Desired Hue to Any Garden
By Dr. Leonard Perry
University of Vermont
Blue Grape Hyacinths, or muscari, create a magnificent river at the Keukenhof display garden in Holland. Thalia Daffodils are used on the sides.
Blue is probably the least common color in the garden. While not common among flowers, it is even less common among other plant parts. Of course, there are the blue leaves of rue, some hostas, some ornamental grasses and blue spruce. And there are blue fruits on some perennials, such as the Solomon's Seal (Polygonatum); vines, such as the porcelain berry (Ampelopsis); and shrubs, such as the arrowwood (Viburnum).
Being an uncommon color, blue flowers can add variety to a garden. They also can be used to evoke the perception of distance, the feeling of relaxation, or mirror "blue" moods. There are probably more blue flowers available for your garden than you might imagine.
In A Book of Blue Flowers, Robert Geneve lists 44 main families of ornamental plants containing blue flowers. Some families contain more than others, such as the Aster, Borage, Bellflower, Mint, Lily, Snapdragon, and Nightshade families. But not all members of a genus are normally blue.
If the species name is caerulea, cyanea, or azurea, it's likely that the foliage or flower is blue or has a blue tint. There are many cultivars among the various families with names such as 'Heavenly Blue,' 'Sky Blue,' or 'Blue Star.' Keeping this in mind—that not all members of a genus are usually blue—here are some examples of various plant groups and uses.
For annual bedding plants you might consider Ageratum (floss flower) or Torenia for low clumpers; Scaevola (blue fan flower), petunia, or verbena for low spreaders; sweet pea for a climber; and tall ageratum or mealycup sage (Salvia farinacea) for tall backgrounds.
Looking for a blue-colored flower for a hanging basket? Consider Browallia,
Lobelia, petunia, or Scaevola. For specimen plants or containers consider
Agapanthus, hydrangea, or Plumbago.
Blue Star Sea Holly is one of Dutch Gardens' most popular perennials, no doubt, in part, because it is blue.
Some flowers, such as this Blueberry Sundae Daylily are not true blue; however, it merits being called "blue" because few flowers in this genus come even close to being blue.
Vines with blue flowers include clematis, morning glory, and for warm climates, wisteria and passionflower. For cut flowers you might use tall ageratum, the bulb Camassia, Eustoma (prairie gentian), iris, lavender, statice, lupine, scabiosa, or Perovskia (Russian Sage).
Bulbs that add blue to your garden include Alliums (ornamental onions), Camassia, crocuses, hyacinths, Muscari (grape hyacinth) and iris. Some irises also may be used around ponds as can some water lilies and pickerel weed (Pontederia).
Some perennials for shade, in addition to the blue-leaved hosta cultivars (often with "blue" in the name), include Ajuga (bugleweed) and Vinca ground covers; forget-me-not (Myosotis), Jacob's ladder (Polemonium), some primroses, and many lungworts (Pulmonaria). Perennials for sun in spring include Ajuga, columbine, Baptisia, Camassia, and Symphytum.
Amazed by the number of blue flowers? The list continues with summer perennials for sun, such as Agastache, Amsonia, Campanula, Centaurea, Delphinium, Echinops, Geranium, Iris, Lavandula, Limonium, Lupinus, Nepeta, Perovsia, Phlox, Platycodon, Salvia, Scabiosa, and Veronica, among others. For autumn bloom, try blue asters and Caryopteris.
This growing season, why not start singing the blues in your flower garden by incorporating some blue-flowered cultivars in existing beds. Or design a monochromatic blue bed for all-season flowering.
Leonard Perry is a professor at the Univeristy of Vermont in Burlington, Vt. To see more of his articles, go to Perry's Perennial Pages.
"I know that people don't usually put bluebells and Las Vegas in the same sentence. But this bit of our garden is almost totally in the shade of a tree. It was really lovely to see masses of blue in early spring—or what it late winter elsewhere." Photo by Pat of Las Vegas, Nv.
"I planted this blue hydrangea next to my yellow daylilies this summer. I love the contrast between the yellow and blues." Photo by Krista of Groton, Mass.