Journal of Horticulture and Practical Gardening (n.s.) 17: 99-100 (Aug 5, 1869)

ON THE PROSPECTS OF HYBRIDISATION.
R. T. Clarke

The object of the following remarks is to show how large a field is still open to culturists in the matter of cross-breeding.

In order to see the extent and nature of this I will ask you to withdraw your attention to a considerable degree from the mere in-and-in breeding of a few favourite and already over-bred groups of garden plants, and to turn it to the higher object of originating new forms and qualities, by working with hitherto neglected or unthought-of subjects. under this head I include:—

Genera hitherto unattempted.

True species unused, or insufficiently worked out.

Old garden plants, shrubs, or trees possessing high special qualities.

Variegated plants of all kinds to be used as the sires or male plants.

Other descriptions might be catalogued, but the above list would give us enough to do. I will not treat these cases separately, for they are much bound up with one another, but will take them as they happen to suit my present purpose, which is to say as much as I can in the shortest space of time.

Let us begin with ordinary cultivated things—the old familiar forms of the flower or kitchen garden, and note a few of our shortcomings. Enter genus Rosa:— The Rose has been said to be coming rapidly to a dead lock, so great has been its cultural improvement. But this improvement has run somewhat in a rut, hundreds and thousands of seedlings are raised annually, and yet we get little more than slightly improved forms of a few favourite types.

It is not my province here to point out the means of working to a given standard of perfection; this is the task of the skilled and practised craftsman whom we call the florist. The hybridist is the explorer and pioneer, after him comes the selective improver. I will not taunt my florist friends by saying, You have not yet produced a blue Rose; but let me just observe that the greater part of your show Roses have no scent, and many of them neither scent nor constitution. Your yellow Noisettes won't open; and of the perpetual, or Provence classes, you have no scented yellow Rose at all. Neither have you a white one fragrant and ever-blooming. Sweet odour, that complementary quality which, with other matchless attributes, makes the Rose of romance the real Rose of the poet and the lover, is absent. The scent of the Rose called Mademoiselle Bonnaire would never recall a memory. Again, you have no crimson Tea-scented Rose; you have no really good rampant or climbing perpetual Rose at all. Fellenberg and Eclair de Jupiter are far from perfection. Where is the very possible perpetual Pompone? With July we bid a long adieu, alas, to Rose de Meaux. Can these deficiencies be supplied? I think they can.

First let us lay the foundation for a white, by crossing together the white China and the white Unique Provence; also the whitest Tea, say Niphetos, with the same, and the old white Moss. For a blush-coloured race, take the fragrant old Maiden's Blush and Celeste, and cross with the pink-tinted Teas. For size and doubleness of flower, with fragrance, take Souvenir de la Malmaison and Comtesse Lacépède, and cross with White Provence and Moss with Maiden's Blush, even with the Common Moss and Cabbage Rose.

The production of a yellow will be more of a task. As seed-bearing parents let us take the old yellow China; it is still to be had, though very scarce; the yellowest Teas with the white China and old Sweet Double White. Cross these with the Austrian and Persian Briars. Also cross together the yellow Teas and China with the palest and clearest-coloured Provence kinds.

The Teas should be fruited in pots under glass. This will bring them into flower at the same time with the Austrian Briar. Moreover, they set their fruit freely when grown in this manner. For a high-coloured Tea Rose, the old crimson China Semperflorens would impart a large share of its colour to any of the true Teas, and the cross might be taken both ways.

It will probably take some generations to produce a good rich-coloured climber Fellenberg. Gloire de Rosomène and crimson China might be crossed together. Ruga, which seeds freely, might produce seedlings of higher colour and frequent-flowering habit by a cross with these last-named kinds, and for an experiment their pollen might be used to fertilise Coupe d'Hebe and Fulgens. The sluggishly-opening, Tea Noisettes might be crossed with the old semi-double yellow China to produce an intermediate effect. I may here suggest that the noble old Noisette Grandiflora should make a fine seed-bearing parent when crossed with handsome vigorous Roses of almost any class, but especially the Provence breed.

Again, to originate new and hardy races there is sufficient evidence to prove the enormous advance frequently made by a first cross from a wild or natural species with the pollen of a cultivated one. I need only point here to Ruga and Maria Leonida, raised from two wild single species, by the pollen of the double Tea Roses; and the pollen of this exquisitely fragrant plant should be tried upon every natural species that can be procured.

I fear I have dwelt too long upon the Rose, but it was tempting — the Rose always is tempting. Moreover, it was a good subject for an endeavour to shadow forth my meaning to-day.

And now we will take a turn in the orchard. A few good Apples and Pears have been raised by definite and well-considered crosses, but many yet remain to be devised and carried out. One of the first things that will occur to us, when once out of the old rut, is that we hare scarcely any good summer Apples and Pears; none of any size, and none possessing the peculiar and higher qualities of the autumnal and winter lands. Who has ever raised a seed of Citron des Carmes, or reared a brood of young Jargonelles, ennobled by the blood of Marie Louise, or other early autumn Pear? Who has ever collected, selected, and united in wedlock the pleasant but very improvable summer Apples? I think no one, as yet, not even the great Sultan of Sawbridgeworth. Is there any reason why the great size and hardy vigour of the Catillac and other culinary Pears should not be imparted to or shared by those sorts whose melting flesh and rich flavour fit them for the dessert table? Mr. Rivers has worked nobly at the stone fruits, and especially as regards the Peach, Nectarine, and Apricot groups; but there is yet a most interesting and important line of work left open to the horticulturist— viz., the breeding expressly for hardiness. Hardy Peaches and Apricots are known to exist. Let these be searched for, collected, and bred from; let them be sown, reared, and, if possible, fruited away from the sheltering wall. The long frosts of winter, and capricious climatic vicissitudes of spring, will of themselves form an effectual selective process. In all crossing experiments, hardiness should be kept prominently in view — hardiness of constitution generally, and hardiness to bear low temperature. It is common enough to hear it said, "Such a fruit is the king of its race, but it is so tender, or, it may be, such a bad bearer."

Should such things be when the cross-breeder has actually the power in his hands to combine given qualities and to impart deficient ones? Much attention has been given of late to the Plum, and we possess many fine sorts; but there still remains many a curious and haply profitable combination to be tried. The pretty and curious Cherry Plum has not yet been used as a parent. The hardy and prolific Damson would certainly produce valuable orchard sorts, if crossed with the Green Gage, Golden Drop, and other kinds possessing high quality and marked character. The common Bullace is a less promising subject, but it is in itself quaint and pretty as a dessert fruit, and might repay the trouble of crossing with the Golden Drop. Even the poor despised Sloe would furnish an importantly instructive experiment in showing to what an extent the austerity of its wild produce would be modified by the influence of a rich and saccharine garden Plum.

I do not think much deliberate crossing has been done with the Cherries. A few subjects of well-defined races might be crossed together. The Morello produced sterile seedlings when experimented upon by Thomas Andrew Knight, yet I cannot help thinking that further trials might meet with success, or at any rate verify a result. I need hardly say that to a really scientific mind the verification of an experiment, or the setting at rest of an old doubt, is a gratification of the highest order.

After the fruit tree question, of which I fear you must be almost tired, we pass naturally to the shrubs. Are our small fruits incapable of farther improvement? Not while Red Currants are sour, and — I now address myself to an especial audience, — Men of Lancashire, I call upon you to produce an eatable prize Gooseberry. Red Currants still obstinately persist in being acid, although they were once worked at by a master hand; but a few generations under the care of the hybridist would undoubtedly improve the Gooseberry in flavour as well as in size. Your huge Lancashire Roaring Lions might be made rich with the honied juices of the old Rough Green, Red, and Yellow berries, and the "unsapid" pachydermatous, prize-taking monster might become a mouthful for a prince.

I had prepared materials for carrying out far more fully my intention in treating of this subject. Time flies, and I have only got to Gooseberries.

So now I will bring my fragment, for it can perforce be no better, to an abrupt conclusion. I hope I have inculcated an important principle, to wit, the getting oat of a rut; and I wish all good fortune and success to the bold traveller in untrodden ways.—R. T. Clarke.

P.S.—There is no earthly reason why we should not cross the Pine Apple.