Everybody seems to love columbines with their delicate, exquisite beauty, both elegant and elusive. The Rocky Mt. Columbine is the state flower of Colorado and yet we seldom, if ever, see front yards swaying with masses of their classic loveliness. What is the story or trick to growing these plants successfully in Colorado? Because of my own mixed success with columbines, I decided for this article, to add the experience of other gardeners to my personal views.
The first level of response from experts like Bob Nold and Panayoti Kelaidis is that columbines are easy. Certainly garden centers are full of gorgeous columbines in many colors, so alluring they have been called “eye candy”. And everybody has enjoyed the blooms right after planting these in the garden. But the second level of response from these great gardeners is, “yes, they are easy, but…”
So at this point I am going to go into some of the particulars of columbines that might sort out some of the confusion. Understanding the native habitat of columbines gives us some clues as to what they like in the garden. Most columbines, and all Colorado native columbines, grow in the mountains. Those that grow in full sun are mostly at higher elevations. Lower in the foothills, they prefer growing in shaded canyons and under aspens and conifers. You never see them out in the open plains. And natively, columbines grow in lean, well-drained soils that are moist in the spring and drier in summer, usually in cooler and shadier conditions.
So what is easy about columbines? Most are well-adapted to our winter cold and our alkaline soils. They generally like moist springs and drier summers, like we have. And they often self seed, so if they like where they are, they can make several plants from the one planted. Because columbines are tap-rooted, the seedlings are often tougher than those planted from a pot because the root has not been interrupted from growing straight down. Bob Nold says “…there are hundreds of gardens with zillions of columbines growing in them….”
Then what is difficult about columbines? Even though our springs are often moist enough, our summers are too dry. Most columbines are not truly xeric, so they need irrigation to thrive. The trouble is, most of us are trying to grow columbines not in the mountains but on the plains, and here the soil is not only drier, but it is usually clay. When we irrigate, we often create conditions that are not dry enough at the crown (soil level) of the plant. With not enough oxygen in the soil, columbines are susceptible to fungus problems like powdery mildew and crown rot. Stress magnetizes crown borers and too much water and rich soils encourages aphids, especially on the Aquilegia vulgaris varieties. In addition, columbines are often short lived. Who said just because they are perennial that they should be immortal? But it is very disappointing when they only last one or two years. Marcia Tatroe said that under her sandy conditions, columbines are often annuals, though they come back from seed. Bob Nold said that dead-heading can improve longevity. Panayoti Kelaidis said columbines usually last two or three years and then disappear. In his experience the longest lived are Aquilegia desertorum, A. pyrenaica and A. chrysantha. Another difficulty with columbines is that there are no genetic barriers between most of the species, so many species cross with each other. This has several consequences: one is that pure seed is hard to find, garden-collected seed being notoriously unpredictable. And even wild-collected seed is not always reliable. This is why it is not uncommon for people to be frustrated when they buy a Rocky Mt. Columbine and find out that its bloom doesn’t have that classic blue and white coloration that you see in books. Another consequence of free sex between columbines is that many people report that their columbine “changed colors.” This phenomenon occurs when the original plant dies and its seedling that comes up in roughly the same place, is the result of some clandestine meeting and is a different color from the parent. There is, however, a happier consequence of columbines’ notorious promiscuity. The self-sown seedlings, because of their high variability, are sometimes better adapted than their parents.
Panayoti Kelaidis took advantage of this phenomenon when he watched a group of Aquilegia chrysanthas over several years and picked out certain exceptional individuals that eventually became the “Denver Gold” selection that was made Plant Select in 2001. This selection is one of the best-adapted columbines both to sunnier and drier plains garden conditions. Marcia Tatroe told me that the columbine hybrids she planted quickly perished, but their seedlings have live on for years, one patch in sunnier conditions being a dark purple and a shadier group being yellow and red. My own experience is similar, with certain groups of columbines coming back for many years, shifting sometimes in color, and not always to my liking. The great rock gardener Lincoln Foster wrote “…they intermarry with the undistinguished to gain longevity and awkwardness.” So the gardener has the option, as with any self-seeding plants to weed out the undesirable colors and forms, and to cultivate selections adapted to their conditions.
Of course, much more could be said about these wonderful plants with their delicate, lacy foliage, their stunning 5 petal-like sepals and their usual elegant curving spurs containing nectar. However more detailed information can be found in Bob Nold’s book Columbines. To whet your appetite, I will briefly describe a few columbines that have good records of success in Colorado.
The meaning of “Aquilegia” is variously defined. The most likely derivation is from “aqua” (water) and “legere” (to collect), from the way nectar is collected at the base of the spur. Also possible is “aquilegus” (water drawer) from the way the taproot draws water from below.
Aquilegia chrysantha, the yellow columbine is perhaps the easiest, most forgiving and most reliable landscape columbine. It is a Colorado native from the canyons of southern foothills and from New Mexico and Texas. It grows 2’-4’ high and can tolerate sun, heat and drier conditions, but also full shade. It can self-sow vigorously to form colonies. “Yellow Queen” is frequently available and the 2001 Plant Select winner “Denver Gold” is an enduring and long-blooming selection. Somewhat similar and perhaps related is Aquilegia longissima, with very long spurs and later blooming.
Aquilegia coerulea is the Rocky Mt. Columbine from moist meadows and aspen groves from 5000’-12,000’ elevation. It grows 15”-30” tall with sky blue sepals and white blades. Though sometimes considered biennial or unsuccessful in gardens, I had one live for 5 or 6 years on the north side of a gravelly hill. This year I hope to see bloom from a form I grew from seed as Aquilegia coerulea ‘Alba’ which I’m hoping will be tougher than white Aquilegia vulgaris forms that didn’t like my garden. Nold calls the form ‘Crimson Star’ “…a gorgeous thing….”
Aquilegia desertorum, the Arizona Columbine, is successful here, but despite its name, it is not drought tolerant. It is, however, heat tolerant and long-blooming and grows to about 12”- 18” high, with small nodding red and yellow flowers.
Aquilegia scopulorum, the Rock Columbine, is one that has been successful and long-lived for Marcia Tatroe. Bob Nold says it needs plenty of moisture in spring and was not long-lived for him. He adds that “…in full flower, this is possibly the most beautiful plant in the rock garden.” It appears to be quite variable, growing 4”-16” high and blooming either blue or blue and white. A Utah source claimed that it is more sun and drought tolerant than most.
Aquilegia barnebyi is native both in Colorado and Utah, growing in cliff walls and shale outcrops. Its foliage is very attractive, almost blue and very dense, unlike most columbines. It grows 12”-16” tall and wide and blooms prolifically with small nodding pink and yellow flowers. It has a huge tap root and was called by Marcia Tatroe “a true low water columbine”. Bob Nold says his has been long-lived in full sun in a dry, clay-based rock garden. I have had great results with A. barnebyi in dry part-shade.
High altitude Colorado native, Aquilegia saximontana has been long-lived for Panayoti Kelaidis in troughs, and Aquilegia jonesii has also done well for him in troughs. Bob Nold says A. jonesii is a small plant, 3”x8”, with big purple flowers. Although it has a reputation for being difficult to grow, Bob assures us that in Denver anyone can grow it if it is kept dry, like a cactus.
The common Aquilegia vulgaris likes moisture, gets aphids easily, comes in many colors and varieties and is “indestructible” when happy. My wife, Eve, has grown Aquilegia viridiflora for years for its exquisite sweet fragrance. Its green and dull maroon flowers are subtle but pretty and now after many years, it has slipped away from her garden. And no doubt, many of you have loved and lost other varieties and species.
In conclusion, I would say that columbines are like children: easy AND difficult. Try to give them cooler conditions with well-drained soil, moist in spring and neither soggy nor dry in summer. Deadhead for longevity, fertilize sparingly and weed out the seedlings with undesirable colors and forms. Columbines are in our care, not under our control; and when they are at their best, let yourself gasp at their breath-taking beauty.