On a recent trip to the botanic gardens, I was captivated by a constellation of tiny blue flowers, stars spread on tender green leaves in the shade of some mature pines. Five azure petals surrounded a hollow white center on blossoms under a quarter inch in diameter. They bloomed in profusion, an inverted sky beneath my feet.
It looks like the sky has fallen and landed among my perennials. Purple-blue flowers formed a dense carpet nearly obscuring the thick layer of green foliage underneath—and the whole show was only a few inches high. I have a weakness for “blue” flowers (when it comes to botanical descriptions, usually that means purple), and the various speedwells are at the top of my list.
It’s easy to understand why we want to include Sweet William, Lamb’s Ears, or Love-in-a-Mist in our gardens. Their whimsical names make us smile. On the other hand, it’s surprising anyone grows plants with names such as fumewort, blood lily, or wormwood. They sound awful! In fact, these plants are quite beautiful, as you can see below (clockwise from upper right).
Who doesn’t like blue? With clouds of sky-blue, 5-petaled flowers that seem to float among the surrounding foliage, Blue Flax is a welcome addition to any garden. A perennial hardy to 9,500 feet, the fountain-shaped plants are comprised of graceful, wiry stems reaching two feet in height, and embellished with blue-green needle-like leaves.
Flax’s open, airy stems tend to go unnoticed, but the abundant true-blue flowers will fill those empty spaces between more vibrantly colored blooms in a perennial border. However, flax is most at home naturalized into a grassy meadow, where it can mingle with blue gramma grass and other short-grass prairie wildflowers.
Colorado has a love affair with the blue spruce (Picea pungens). Perhaps we’re enamored with the striking, steel-blue tint to the needles, and the way the color causes fall’s orange leaves to glow. Perhaps we appreciate the towering, pyramidal shape of a mature tree, or the short and squat dimensions of a dwarf cultivar.
A number of gardeners I’ve talked to added a blue spruce to their yard because it’s Colorado’s state tree. Blue spruces may not be the easiest species for Front Range landscapes, but they’re definitely worth the effort.
Spring flowers have turned into berries and seed pods. Without their blossoms peonies are mere green bushes, and even the annuals are looking a bit peaked. Don’t despair, however. The show isn’t over yet. One of the best perennials (or small shrubs) for Colorado gardens is Caryopteris x clandoensis, more familiarly known as Bluebeard or Blue Mist Spiraea.
The latter common name can cause some confusion. Caryopteris isn’t a true spiraea. The “Blue Mist” part is spot on. The airy flowers in periwinkle blue really do seem to hover over the tips of the stems in a lovely cloud. The plants can reach two to three feet wide and tall. Foliage is a bluish gray-green, with long, soft, serrated leaves.
Like many gardeners, I have a “thing” for blue flowers. Lobelia (below), Blue Mist Spiraea, cornflower (Bachelor’s Buttons), and Borage all find a spot in my garden. I’d love to include Himalayan Blue Poppies, hydrangeas, and morning glories but they don’t do as well in my soil and climate. (The poppies need constantly damp soil, hydrangeas need acidic soil to turn them blue plus they’re not hardy enough. The morning glories do well in my greenhouse, but outdoors they usually freeze before them get around to blooming.)