Things Every Breeder Should Know
by G. G. Nearing
From a talk given to the New Jersey Chapter
What does a breeder of rhododendrons or of any other ornamental plants aim to accomplish? The answer is simple. He wants to produce new varieties which will find favor with those who garden. Who is to decide whether he succeeds or not? The gardening public.
Of course the average member of the public has only average good taste, but he does look for guidance from writers and landscape architects, some of whom are well able to judge the quality of a new introduction.
Landscape architecture is in some respects the most difficult of all the arts. Like painting it depends on color and composition (design). Like sculpture it deals with form in three dimensions. But it requires also a knowledge of horticulture and botany, and the ability to visualize what plants will look like ten or twenty years from the day they are planted.
To win the approval of trained landscape architects, a new rhododendron variety must first of all be beautiful, with pleasing form, attractive foliage, and color which will harmonize readily with other flowers of the same season. It is possible to succeed for a whole with shades which are merely vivid, because these do attract attention, and may win temporary favor with the masses. But rhododendrons take so long to establish, that cheap, quick success is seldom worth while. Each variety must stand up under years of critical judgment by the experts, if it is to justify the long, laborious building up of stock which is invariably necessary.
The study of color is a field which every breeder should try to master. Matching shades with a chart is not sufficient. For the creation of colors it is necessary to imagine in colors, to think in terms of the fundamental nature of color. Everybody knows that there are three primary colors, red, yellow and blue, while black is the absence of color. But what about white? We are told that it is a mingling of all colors, yet if you mix colored pigments, you cannot arrive at white. The mixing of pigments gives results different from the blending of colored lights, while in flowers some shades are produced by colored particles, others by colored juices, still others by reflections.
Under each primary color are included countless shades, from pale to dark, from dull to vivid, from pure to slightly mixed with other primaries. Thus a red with a very little yellow in it becomes scarlet, with a touch of blue, crimson.
Secondary colors in pigments are made by mixing primaries. Combine blue with yellow, and you have green, blue with red, and you get purple, red with yellow, producing orange, but here too are countless shades. Mix all three to create brown if the red predominates, buff if yellow is dominant, and gray if blue is the major element. All these facts must be thoroughly understood, but the exceptions to them are equally important. If you mix colored lights, you do not get the same results as with pigments, and if you cross a yellow rhododendron with a red one, you will probably find the offspring lavender.
Color harmony is a matter so intricate that only an expert can depend on producing it, yet anyone can learn whether two given shades will harmonize. Hold them apart, then bring them slowly together. If, as they approach each other, each takes on a higher degree of beauty, then they make a harmony. But if each looks tawdry and cheap as it draws near the other, those colors are said to clash. By repeatedly moving them together and away, even an insensitive eye can learn to judge each pair of colors.
Experience and long familiarity teach us which colors are going to harmonize and which will clash. Different reds seldom harmonize with each other, yet red is the most popular of all colors because the most vivid. The daring artist will trust his skill to use more than one red without creating a clash. It can be done, but not usually by a novice. Yellows and blues go more easily together with their own kind, but even here, experience will call a warning.
In the region between red and blue are many shades which do not please the eye nor harmonize readily. A color-ignorant public, misled by half informed "experts," calls these magenta and condemns them. Magenta is an intense red with only a little blue in it, and is a popular shade under other names. Reginald Farrer is to blame in part for this misnomer. He called the objectionable shades magenta pink, because if you mix white with pure red, you get pure pink, but if you mix white with magenta, you get a purplish pink, the color generally and rightly condemned.
But many writers are evidently color-blind, and not understanding what shades they are supposed to revile, damn all purples, including beautiful violet and royal purple. It may also take generations to live down this nonsense.
Between red and yellow on the color chart, we have a long series of shades from orange to yellow, with salmon, peach and apricot, virtually all of which are desirable. Comparatively few of the flowers in nature run to these beautiful tints, while the great majority favor purplish pinks, the colors we do not like. Thus the breeder is, in one sense, working against nature.
It would be well if every breeder took a course in art school to sensitize his sight for the color problems he must inevitably face. Yet color alone, though it may win a blue ribbon in a flower show, is only one element in the many-sided program of producing landscape beauty. The form of a plant is more difficult to define than the hue of its blossoms, and here again, a course in design at the same art school would help to keep a breeder on his toes. When you draw a series of lines, they may be ugly or meaningless or beautiful. All depends on their relations to each other. Modern art favors the meaningless, but for the landscape gardener, beauty is still essential.
When a rhododendron grows a branch, the angle at which it leaves the main stem may please or displease the eye. The manner in which the leaves join the stem may be just right or all wrong. And so on through every detail of the make-up of any plant. Some grow into pleasing forms, others do not. Although there is no rigid pattern into which a Rhododendron must fit in order to win public acclaim, most of those clones which have held gardeners enthralled for a century or more, do show a similarity of form, and its fundamentals are worth studying. Essentially the mature plant is a green dome touching the ground on all sides, while the leaves overlap shingle-fashion, to hide nearly all that stands within the dome. The flowers are lesser domes of color rising from various parts of the plant. Other plant patterns may appeal to the eye in other ways, but this one has earned for the typical Rhododendron a unique place in the landscape.
A trained eye will evaluate almost any rhododendron after a few glances, estimating whether the plant can take its place as the expected superb unit of landscape design. But several questions remain to be answered. Is it hardy? Is it reasonably free from disease? Can it be propagated rapidly? Will it bear transplanting without loss of vigor?
If it is to have a future in gardens, all or most of these questions must be answered in the affirmative. Some breeders prefer to let the public discover the answers, but the public will build up less enthusiasm after each failure. A breeder who values his reputation will not risk failures, but will offer only plants sure to please.
Of course there are exceptional cases. A clone with some outstanding new shade of color, even though not completely hardy, or not too easily propagated, may be worth putting on the market with appropriate warnings. Nothing in this world is perfect. But the man who indulges in such exceptions habitually will soon find himself bogged down in a clutter of inconsequential and unpopular trash.
Important also is the season of flowering. If too early, the bloom may be caught by frost; if too late, summer heat may wilt it. New growth appearing before the flowers have faded, may not absolutely rule out a rhododendron. R. 'Boule de Neige' in some seasons is guilty of this shortcoming. But a serious shortcoming it is, and any plant having it, must show many really superior virtues to offset it.
The length of time during which flowers maintain their beauty, is another feature of great importance. Some corollas fall only three or four days after opening, while others last nearly two weeks. Some turn brown around the edges after being blown upon by a mild breeze; others keep their color through all reasonable wind and weather.
The shape of the truss is not subject to any fixed rule.
R. williamsianum
has no truss, yet is universally recognized as a thing of rare beauty. The floppy trusses of Fortunei hybrids may look shabby or aristocratic, depending on just how they flop. A truss of superior dome shape may have the florets too crowded or too widely spaced, or just right. Sometimes the form of the floret harmonizes with the form of the truss, sometimes not. Some trusses look well seated tightly on the leaf rosette. In other cases it is held high, and in either event, it may please or displease the eye.
Drooping leaves, or leaves that stand out stiffly or point upward, each may prove ornamental or undesirable, according as they harmonize with the design of the entire plant and the manner in which its flowers are borne. Deep green color usually looks better than yellow-green, but there is a place for both. The foliage may be polished or dull. Some leaves are pleasing in outline, while others have an essentially ugly shape. Some may arch upward, others lie flat, or have their edges waved or upturned. No rule governs the leaf pattern except the rule of eye. If it looks well, it is good.
But generally speaking, abundant foliage is more desirable than sparse, dense branching better than open, short growth between the leaf rosettes better than long. A compact plant makes a more beautiful specimen than a. rangy one.
There is a place for dwarfs to be used for edgings and in rock gardens. But unthrifty plants do not look well whether large or small, and those which grow too slowly will seldom please the majority, or the nurseryman. To become really popular, a shrub must shape up in reasonable time.
A favorite trick of nurserymen is to take a seedling which resembles an established variety but is not quite as good, and sell it under the name of that variety. This of course is cheating, and no self-respecting breeder would be guilty of it. But many an innocent grower has been misled into accepting the plant which is not true, because he could not see the difference. Thus we have a fraudulent R. 'Everestianum' which is less hardy, less graceful, and inferior in color, but which propagates more easily than R. 'Everestianum,' and is therefore crowding out the true clone. I have learned the difference, and recently destroyed all the fraudulent plants in my stock.
Because seedlings of R. 'Roseum Elegans' tend to resemble their parent, hundreds of different clones are now being sold under that name, with flowers ranging all the way from the original pink to poor lavenders and various shades of the purplish pink miscalled magenta. In fact, the true variety is now hard to find.
Worse still, millions of seedlings are being sold as hybrid rhododendrons. They are hybrids, so the marketer is not a liar, but he is doing irreparable harm to the popularity of rhododendrons, for most of the plants are worthless from every angle.