I have to admit that when it comes to gardening, I’m a sun lover and many of my favorite plants are for sunny planting sites. But I live and garden in the high desert of northern New Mexico, where shade is a scarce community. Yet even in Santa Fe, the oldest parts of town have mature trees and the yards there are more shade than sun. This is the case in much of the western U.S. as well.
The Challenge of Shade
There are several types of shady planting sites. And the difference is important in the plants we choose. The most challenging shade is under shallow rooted shade trees and tall conifers (evergreen trees). Not only are their roots highly competitive with any plants placed under them, but this ground is in permanent drought because the tree canopies absorb much of the rain and snow that falls on them. So the plants placed here need to be both vigorous and xeric (drought tolerant).
Other parts of the yard have shade from overhead branches and buildings. The north sides of buildings and fences are often quite shady, especially if the buildings are two stories tall. But the root competition is often not as severe as directly under tall trees and large shrubs. So our plant choices are expanded.
The Graceful Beauty of Columbine
For parts of the yard not directly under the large trees, Columbine (Aquilegia) is one of our very best perennial general for shade. They also appreciate more moisture, so the north sides of fences and buildings are especially to their liking. Columbine are also a favorite of hummingbirds, with their sweeping spurs a source of ample nectar for our winged jewels.
The most famous columbine is Aquilegia caerulea, the Rocky Mountain columbine. It’s the state flower of Colorado, but is widespread across the higher elevation spine of the Intermountain West. This blue and white beauty is not for every yard as R.M. columbine requires the cool to cold nights and modest day temperatures, characteristic of elevations over about 5,000 ft. Although I strongly suspect it will thrive in higher elevations of the Great Smoky Mountains and eastern mountains of New York and adjacent states.
My other favorite columbines include:
Arizona Columbine (Aquilegia desertorum) – a long blooming species with cheerful orange and yellow flowers. Native to the mid-elevations of Arizona it is tolerant to more sun and drier conditions than most.
Swallowtail Columbine (Aquilegia sp. Swallowtail®) – an exceeding rare plant in nature, originally collected from a hidden canyon in southern Arizona just north of the Mexican border. The flowers are large and stunning with trailing spurs up to 4” in length. Fantastic blue foliage! Heat tolerant too.
You’ll notice that we specialize in un-hybridized columbine. Columbine as individual plants are not long lived; three to four years would be typical. But Aquilegia are colonizers, re-seeding themselves to create long-lived colonies. While hybrid columbine give the garden a wonderful blast of color, they will re-seed themselves into a colony of muddy yellow flowers. By planting species or stabilized hybrids (come true from seed) unmixed with other species, you’ll create a true seeding colony of colorful bloomers. Where possible, try and separate your columbines apart in distant parts of your yard to minimize cross pollination. Or go ahead and mix the species and simply re-plant every few years.