"C" is for Clarkia and Confusion
By Norman DeNeal

Now that the bicentennial of the Lewis and Clark Expedition is approaching, there is increasing interest in the flowers that the journey encountered. One such plant is clarkia, named after the Corps of Discovery's co-leader Captain William Clark. Actually, the expedition came upon only one of the 36 annual species of clarkia since discovered. That species, Clarkia pulchella, found in Montana, is a species unfamiliar to most who know something of clarkia. Described by Clark on May 29th, 1806, and by Lewis on June 1st, 1806, on their return through Montana both described the flowers as light purple, though they are pink with a hint of either lavender or red. Sometimes white flowers occur sporadically. In most color mixes the white flowers are about a third of the mix.

Clarkia pulchella

Clarkias have a convoluted history, and to this day the literature of cultivation on them is littered with error. Also, part of the byzantine clarkia story is simply that many clarkia were mistaken for other genera such as Godetia or Eucharidiums. But most importantly, the cultivation literature almost always stresses growing clarkias in poor soils lest lush leaves be grown at the expense of flowers. While true of a few species, the truth is that most clarkia prefer at least moderately fertile soils and even sometimes a rich soil. Here we will concentrate on three species.

The clarkia that most are familiar with is Clarkia unguiculata, often still called Clarkia elegans. Commonly it is called "Rocky Mountain garland," even though it is a native of California (which is not a part of the Rocky Mountain chain). The variety usually available is a double flowered mixture known as the "Royal Bouquet Series." It grows about 10-12 inches tall, and has about 6-10 flowers ascending on each of the 3-6 stalks per plant. It resembles a small double hollyhock. However, in rich soil, the plant can reach 18 inches in height and have 10-15 stalks with a total width of 12 inches. But in such rich conditions, its gluttonous and lavish life usually ends without producing seed. Most notable with this species is that its flowers are of spectacular eye-catching color...clear pink, salmon, and light purple are the most common, with sometimes an occasional white or red. Often listed as a good cut flower, in truth it looks mediocre after only a couple of hours in water. It blooms for about a four-week period.

A little less common is Clarkia amoena (amoena is Latin for attractive or charming). Sometimes in older books it is listed as Godetia amoena or Godetia grandiflora. Commonly it is called either "satin flower" for "farewell to spring." Also a native of California, its cup shaped flowers resemble azaleas, and though one may envision a satin texture for the flowers, they more resemble porcelain. The flowers appear in colors of red, pink and salmon, but usually come in bi-colors with white. Blues and purples are available but they are considerably harder to germinate. Generally the plants are about 8-12 inches tall, though if crowded among other plants they will reach a height of 2 feet. They prefer fertile or moderately fertile soil of at least 4 inches. And though named "farewell to spring" they generally bloom in early August in Montana.

But of all the clarkia species, the one by far best suited to Montana climates is Clarkia pulchella (pulchella is Latin for beautiful), and beautiful it is. Its flowers are enchantingly delicate, the bloom period will last for 6 weeks, and they will self-seed unlike other clarkias whose seed has to be gathered since the seed rarely will survive a Montana winter. Both Lewis and Clark noted that the plant lived in fertile soil, and though it will grow in poor soils, its discoverers were correct in its preferred habitat. Reaching a height of 6-10 inches, it will bloom from self-seeded plants in late June. Sadly, this author has never been able to find the seed of this Montana native other than in Thompson and Morgan, a British seed catalog, which for the last few years has only offered the white variety.

All clarkias prefer to be seeded as soon as the ground can be worked in early April. Keeping the soil moist until the seedlings emerge is an absolute requirement as is well drained soil. With a few individual exceptions the seedlings of all species have red or purple veining in their leaves. A shy plant, Clarkia pulchella emerges within 10 pleasant days, but then laying dormant for nearly 3 weeks before growing further. These clarkias are all moderately drought tolerant. Though the seed should be thinly laid out, they all tolerate crowding. None transplant well.

In short, nomenclature and cultivation requirements are often confusing for clarkia. And because the seed of Clarkia pulchella is so desirable but difficult to obtain, this author hopes to have it available to the Montana Federation of Garden Clubs in the spring of 2004.