No flower runs through a more excellent range of true blue than does the gentian. Since its various species provide bloom from early March to winter snows, it seems strange that gentians are not more often seen in gardens.
Although mainly mountain and rock garden plants, some gentians may be found for almost any situation among some 800 species and numerous worthy hybrids.
Several make beautiful edging plants. Others are at their best along a poolside, and some are pre-admirable for the bog garden.
Gentians’ Various Colors And Sizes
Although most are of the color spoken of as gentian blue, a few depart from the strict color line, mainly among the species that rim to purple tones.
Several whites appear, a few yellows, a brownish red, and one which is reported to be even brighter. Form and size also vary.
Some have huge, fat, upturned trumpets, others slender tubes; some are short and deeply reflexed, resembling petaled stars. A few reach heights of 2’ or 3’ feet; more are miniature scree-clinging plants.
The majority of the excellent garden forms are from 4” to 12” inches in size, the lower ones having several times as much spread around their radiating centers.
Pink-Flowered Gentians
The pink-flowered ones common to New Zealand, the Azores, and South America have now been placed under the genus Centaurium, although they traveled for some time as Erythraea.
Best known of these is Centaurium scilloides, a pink counterpart of Gentians Verna, which rose to fame as Erythraea diffusa and was known before that as Gentians diffusa. This may be some aid in hunting through the nursery catalogs.
How To Properly Grow Gentians
Gentians have a reputation for difficulty, and rightly so among the biennial fringed and high scree gentians.
If a few necessary points in their culture are considered, the majority are as quickly grown as other choice borders, pools, and rock plants.
One significant drawback has been their scarcity, particularly during the war years, but they are now appearing again in lists. One who wishes to make a collection of rarer types still needs to raise many from seed.
I prefer to sow the fine seed in a pot or small seed flat, so I may water from the bottom. Count on a long germination period.
Going over my records through the years, I find them taking from 16 days for June-sown Farrer’s gentian outdoors to 16 months for poorly placed Parry’s gentian on a boathouse porch which was washed over by salt water during a winter storm.
I’ve tried sowing every month in the year, indoors and out, and I believe that outdoor spring-to-June sowings give the quickest results for minor trouble, but I would not hesitate to sow at any time most personally convenient.
Gentians respond well to bottom water, especially if it is percolating beneath. I’ve seen seeds lie dormant for months and then germinate a few days after the flats were set in a tiny creek only an inch deep.
A similar effect can be evolved by using a shallow trough lined with gravel and just enough stream from the hose to keep the water moving slowly.
The choice of gentians should depend upon what we want them to do in our gardens and the fare we can offer them. As a family, winter cold does not bother them.
A good many, however, have difficulty with hot summers unless they have access to moisture in the air. as well as underground, one reason for placing them near a pool.
As a family, too, they like company, their roots in nature intertwining with those of alpine grasses and other plants of their approximate size and sturdiness.
Some are thought to need unknown bacteria in the soil. The most critical point in their culture is that they should be firmly set. Also, hear in mind that all alpine gentians dislike being disturbed.
Low-Growing Varieties
Gentiana Acaulis
One of the most beloved gentians is the spring-flowering gentianella or stemless gentian (Gentians acaulis).
This is a low-growing, large-trumpeted true blue gentian of a more straightforward disposition than many, although, at times, it may disdain a carefully prepared home and flourish in a hard-packed adjoining path.
This is what the gentian horticulturists often recommend for border edgings, poolside, and rock gardens. It will bloom from March to June.
Quite a number formerly listed as distinct species have been reassigned so that purchasers may find considerable differentiation in plants under this name.
Where possible, it is easier to fit the gentian to the garden to obtain these various types of the group, as most variations arise from habitat.
Gentiana Angustifolia
A closely related form, Gentiana Angustifolia (Vill. not Michx.), is usually more free-flowering than Gentiana acaulis.
It is listed for June-July bloom, but I have also found stray blooms in my garden through spring and fall.
It likes moisture in a well-drained, limy loam, while Gentians acaulis prefers somewhat heavy soil with less water.
Gentiana Kochiana
Gentiana kochiana, slightly taller (to 6” inches) and of a darker deep blue with green spots in the throat, blooms from May to June and will not tolerate lime.
Sapphire blue Gentians excise is Reginald Farrer’s favorite of all the group. It is more prominent in all its parts, including the flower, than the others and also dislikes lime. It is exquisitely beautiful, planted by a rock pool or in a rock garden.
Summer And Fall-Flowering Gentians
Several groups carry on blooming through summer and into fall. None of them are more beautiful than the blooms of Gentiana ornate and its close allies, Farrer’s gentian, Gentiana × macaulayi, Gentiana sino-ornata, and Gentiana Hexa-farreri, with other crosses of these likely to appear upon the market soon.
Macaulay’s and Gentians hexafarreri are hybrids, but tile others are among the easiest of all gentians to raise from seed, although some care is needed not to mistake the first shoots for grass.
These gentians form central rosettes of grassy foliage with radiating stems, making prostrate plants 8” to 12” inches in diameter, with large upturned trumpets bore 4” to 6” inches high.
Catalog listings allow about two months’ bloom to each of these, with Gentiana × macaulayi beginning in July, Gentiana sino-ornata in September, and the others in August. However, I have found them extending their bloom for a much longer period.
My favorite Christmas decoration has been a black glass dish filled with the Cami bridge blue trumpets of Gentiana farreri, so beautifully striped with nankeen on their outer side.
Gentiana sino-ornata is sapphire, Gentiana Hexa-farreri deep sky blue, Gentiana Macaulay is bright turquoise, and Gentiana ornata is clear blue striped with purple, blue, and white on the outside. In addition, Gentiana ornata has a more balloon-like trumpet.
Do not give lime to any of this group, as all are acid-lovers except neutral Gentiana Macaulay. A hybrid between Gentians sino-ornata and Gentians farreri. this gentian has a reputation for flowering and behaving well in any good garden situation.
Other summer gentians are only sometimes as clear a blue as those already mentioned. The hybrid Gentians hascombensis has a similar growth habit but is taller and more spreading.
Gentiana septemfida var. lagodechiana is one of its parents, but the hybrid has larger cluster heads of fringed trumpets.
An easy-going July- and August-blooming gentian prefers neutral soil and is a clear blue in its best forms.
Seedlings vary considerably; some go purple, and others have poorer trumpets. However, it is so prolific that the less good plants should be weeded out to build a good strain.
Taller Species
Gentiana Septemfida
Gentiana septemfida, of which the hybrid Gentians hascombensis is a descendant, is a foot-high plant of easy disposition, bearing soft blue bell-shaped flowers in August, which are somewhat smaller than the others mentioned.
For damp or partially shaded places, 30” inches Gentians Asclepiades is often used, with its small narrow azure hells in groups of two or three in the leaf axils.
It makes a good plant for the vacation place toward the end of summer.
Gentians Lulea
Even taller (to 3’ feet) is yellow Gentians Lulea, a large-leaved species far from the large-trumpeted prostrate gentians.
Gentiana scarlatina
The so-called red gentian has a curious flower of Vandyke brown, not a true red. English gentian growers have spoken of scarlet-and-gold gentian, Gentiana scarlatina, which I have yet to see.
A little room should be left for those elusive starlike exquisites that often prove reluctant in gardens yet can reward the “green thumb” with breathtaking beauty. Some are for the pebbly screens, others for moist, peaty rock pockets, preferably near a pool.
Spring Gentian
The spring gentian, Gentians Verna, is one of these. Whoever has seen a sheeting mass of this deep azure blue among a group of rocks, perhaps foiled by the miniature Bowles Black pansy, has known natural beauty.
The starlike flowers of the spring gentian are more effective in mass than in individual plantings. Each carries an airy daintiness as though poised for flight.
April and May are the months listed as their blooming time. This gentian is a small plant about 3” inches high and 4” inches in diameter. The tiny green leaves are spoon-shaped.
It should be planted in a somewhat acid leafy or peaty loam.
Gentiana Angulosa
Gentiana active (Gentiana angulosa) is a larger-flowered, more solid form with a more extended bloom period, sometimes holding well into the fall.
This form is also reported to be more tolerant of garden conditions, but the last time I saw it listed was before the war.
If the rock pocket is wet, use the water-loving Gentiana bavarica, which has more yellow in the green of its leaves.
Gentiana samosa, often found in stony places in New Zealand, is the most frequently grown of the various white gentians.
Although the plant is twice the spread of those mentioned in the paragraph above, it is of the same low 3” inch stature, and the flowers are white-cupped stars rather than trumpets. It blooms in July and August and is like any good neutral garden soil.
In summary, gentians as a family need sun. The real problem is to give them sun without too much heat. They need moisture in the air and moist roots with good drainage. Above all, place them where they can remain undisturbed through the years.
44659 by Anderson Mccully