Propagation Of Roses
( Originally Published 1914 )
IN this chapter it is aimed to give the reader such general information as will enable him to comprehend the main principles of the propagation of the rose. In order that he may fairly understand the following chapters, and the general scheme of the selection of varieties and the ordering of the same, this chapter should be read carefully. It is not the intention to puzzle the home rose grower with all the scientific details of each phase of rose culture; but it is believed that the following paragraphs will give a good working idea of the methods employed. For those who may care to follow out such matters to their utmost conclusion, the names of exhaustive works are given.
Established roses are propagated mainly by the following methods: Seeds, layering and suckers; cuttings, budding and grafting, the last three being the principal methods.
In order to secure established varieties, seeds are used only in special cases, because they can only be relied upon to reproduce plants of their own kind when they are taken from original species. Seeds of hybrids are useless for this end, as their seedlings do not conform to the parent stock. In other words, hybrids do not come true from seeds, and their seeds are only useful for new varieties. "Experiments with Plants," by Osterhout, goes into the scientific treatment of seeds.
Many plants and some roses increase by layering, that is, throwing out a branch which becomes rooted and in turn sends out its branches to root themselves and carry out nature's work of increase. Layering is not practised to any great extent, as it is a longer process than the others and requires not only more time to accomplish results, but also more space either in greenhouse or nursery.
Layering is now only used for some varieties which do not root well from cuttings. Ellwanger cites Persian Yellow as one of these.
It is a simple and easy operation, and is accomplished by bending down a rose cane of a growing plant, scientifically notching it with a knife (technically known as tongueing), and then putting the tongued portion into prepared ground, after which it is held in place by various methods. Roots are formed at the break and eventually the part so treated may be detached from the original plant and becomes itself a complete plant.
Pemberton, in "RosesóTheir History, Development and Cultivation, " gives very clear and explicit instructions on layering.
Pemberton's description of suckers we quote as follows:
"Many of the species, such as RUGOSA, ALPINA, SPINOSISSIMA and LUCIDA, together with Provence,
and Damask hybrids, etc., increase by throwing out suckers, springing up at some distance from the parent plant, and forming roots at the place where they bend upwards. These rooted suckers, after being separated from the plant, should be pruned back to a foot or even less, and then treated as ordinary plants. "
Cuttings are slips taken from plants which, when placed in sand and soil, grow roots of their own and become in turn rose plants, giving the same bloom as the plants from which they were cut. Very often they are given greenhouse care and while this is not necessary, it obtains, perhaps, surer and better results. In experimental work, cuttings have been carried so far that they have been made successfully even from rose leaves, although this method is of no practical use. No doubt many persons who have followed to this point understand cuttings and have employed them not only in roses but in other plants, such as carnations and geraniums, which are propagated almost entirely by this method.
In their proper place cuttings as used in rose culture may be relied upon, but beyond this sphere their use is open to debate, as, in the opinion of nearly all the best authorities, they are not as satisfactory as budding. The main reason for their failure is that many of the new varieties are weak growers and can-not of their own accord win the fight for existence, even under favorable conditions. As conditions in our climate are most uncertain, only the exceptionally hardy plant succeeds on its own roots.
It. would be easy for any one to make cuttings of his own, and this could be successfully done with the hardier roses, thereby saving the expense of purchasing. If roses are purchased, budded plants are strongly recommended, as the slight extra outlay would be fully justified.
While there are many good articles on cuttings, Pemberton's is the best, as it treats of cuttings under glass and also cuttings in the open.
In budding roses a strong stock is secured and the variety selected is budded upon this stock, eventually becoming a part of it. The actual operation of budding is merely to cut off the dormant bud from the variety which it is desired to perpetuate and, cutting a slit in the bark of the stock, to introduce the bud into the same. When the bud so trans-planted becomes somewhat established, all growth above it is removed and the whole vitality of a proved stock is thrown into the bud, giving it the nourishment which a tried constitution insures.
In England the two stocks most commonly used are MANETTI and BRIAR. In the case of roses with a preponderance of Hybrid Perpetual blood the Manetti stock is generally used; for those containing much Tea blood the Briar has been found the better stock.
A few growers in this country are trying Japanese Multiflora, and with some varieties secure stronger and better plants than those grown on the ordinary stocks as generally used. Sometimes Rugosa stock is used for budding and a very few roses do quite well on it.
Undoubtedly the ideal stock for all roses has not yet been discovered, and a great advance should be made in this most important section of rose culture.
In order to secure a perfect rose list, budding on different stocks should be tried. If cuttings are employed, very many roses will not succeed as well for outdoor culture.
There are two objections to budded roses. First, they occasionally break off at the bud, but this has so seldom occurred in actual practice that it is not worth consideration. The second and main reason is that the stocks upon which the roses are budded throw up shoots of their own below the bud, usually called suckers, which, if left, take the entire nourishment of the roots and check the budded growth.
These shoots from below the bud may be very easily detected upon their appearance, because they come up from the ground outside the plant and also because of their different habit of growth, containing, as they do, seven and sometimes nine leaves on each lateral, instead of three and five as in most budded varieties. (Note illustration.) The foliage is of a much lighter shade of green than the shoots from the bud itself and its point of junction with the plant is below the bud. It is very easily removed by care-fully digging up the ground, cutting it off with a knife at its union with the plant below the bud, and rubbing some earth over the cut. In addition, this main reason is not a valid objection, because it only happens with about one per cent. of the budded plants, and can even then be easily detected. To keep this percentage down, roses on Briar and Manetti must be planted with the bud two to three inches below the surface of the soil, as hereafter advocated. If planted less deeply they will grow a greater number of suckers.
Fewer suckers develop from Multiflora than from Briar or Manetti, and on this account George H. Peterson recommends planting the bud from one to one and a half inches below the finished level of the bed. One reason for the lack of suckers is that the Multiflora is budded from seedlings, 'while the Briar is usually budded from cuttings, in which case there are dormant eyes below the point where the bud is inserted; whereas in the seedlings, the bud is inserted below the dormant eyes.
Very often cuttings have only greenhouse growth when shipped. At best they are generally propagated under glass and have not had much outdoor growth, whereas budded plants are budded in the summer out-of-doors, and have even as yearlings a whole season's outside growth before being sold.
In one particular instance the following experiment was made with own root stock.
One bed was made, and over fifty roses on their own roots and fifty budded roses were planted in it side by side, all of old and established varieties, and, in the case of the own root plants, purchased from a grower who advocates their use. At the end of the first summer the difference was plainly apparent and was strongly in favor of the budded plants. At the end of two years there was no possible doubt as to the result; the budded plants were far superior. Experiments with other roses have endorsed this result, and budded roses are recommended for all outdoor work for the majority of roses contained in the lists, whether Hybrid Teas, Hybrid Perpetuals, Teas, Chinas, or Pernetianas.
The roses which do well on their own roots must be secured in two-year-old plants to obtain the best results, and should either be planted in the fall from dormant field grown stock, or planted in the spring from pots after the weather is settled, and for the best results procured from a nursery near at hand. Such plants will become established toward fall and usually give fair results at that time.
In the case of climbers and some few very strong growers the own root roses will give good results, but as a working rule they cannot be recommended. In one garden budded roses, originally planted in the autumn of 1900 and moved to their present place in 1907, are still strong and healthy, and of the original lot less than two per cent. have died in over fifteen years.
In another case budded roses planted over thirty years ago are still flourishing, and this certainly shows that their length of life is all t that can be expected.
In the testing of new roses the great majority has been budded plants and the percentage of deaths has naturally been greater in these new varieties than in established kinds. In importing three hundred to a thousand roses of new varieties, twenty plants a year would cover all the deaths even of these new and untried kinds.
In other branches of horticulture budding and grafting have been tried with the greatest success. It does seem that a tried stock is better than a different stock with each plant, viz., its own.
Undoubtedly better stocks will be discovered for certain roses which do not do well on the regular stocks; but surely it is going backward to grow inferior roses on their own roots and be satisfied with them, rather than experiment to ascertain the best stocks.
"The Nursery Book," by L. H. Bailey, should be read by any one attempting budding.
Grafting is a modification of budding, and is a process which may give as good a result in the end with some outdoor roses; but for the first year, after planting outside, the bush does not make as much progress, and the death-rate has been much greater with grafted stock than with budded plants. Unfortunately grafts do not take very well on the Briar, therefore grafters use the Manetti which, as explained above, is. not the best stock for Teas and Hybrid Teas.
Grafting is mostly used to increase new varieties which, if budded, would necessarily have to be operated upon in the late summer, the bud not developing until the following spring; whereas, in grafting, a part of the plant desired to be propagated is grafted upon the stock indoors and growth at once begins; this is a very much quicker operation, but not so sure of success as budding for outdoor roses.
Grafting requires great skill and is used to obtain quick results. Seedlings to be tested are often grafted and a verdict quickly arrived at. There are numerous methods employed in grafting, but the principle is the same in all; the variety required is spliced on the stock and, as in budding, the strength of the stock all goes into the variety desired.
The books mentioned for cuttings and budding give the best articles on grafting, in addition to which "Parsons on the Rose" contains good, clear and explicit information on all these subjects.
New varieties of roses are developed in two ways : by sports and seedlings.
Sports are purely a matter of chance, and occur when any given variety shows a bloom or habit of growth different from the accepted plant. When this occurs propagation of the wood by cuttings, budding or grafting establishes the new variety.
As illustrations of sports, the two following are well known and are changes from the parent stock in the color of the bloom itself :
La France, color silver rose, sported with Paul & Sons, near London, in 1888, and gave the Duchess of Albany, called dark La France, a rich, deep pink. This was propagated and Duchess of Albany is now a well-established variety.
Camoens, pale rose color with the base of the petals yellow, sported with Boytard, in 1907, and the new rose was called Ecarlate, a brilliant scarlet.
With these two new varieties the habit of growth of the plants remained practically the same as their parents; it was only in the color of the rose that the change manifested itself.
In the past few years the old rose, Killarney, has sported a number of times, giving among others Killarney Brilliant, a rose of a deeper shade of pink; White Killarney, a rose, as the name implies, of a beautiful white; and Double Killarney, a rose of greater substance in petallage than the stock from which it sprang.
Before so many hybrids were cultivated, and when roses were not grown to as great an extent as now, sports were naturally less frequent. Of course varieties which are crosses, such as the hybrids of today, are very much more likely to give different growth or different bloom than the old varieties, which were not so far removed from the original species.
Changes in habit of growth occur as well as changes in bloom, and a great many of the Hybrid Teas and some Polyanthas have produced sports which have much more of a climbing habit than the dwarf bush from which such new varieties originated. The bloom in form and color is practically identical with the parent stock, although its period of flowering is usually shorter and its bloom less profuse.
There is one very interesting illustration of a rose which sported, the new growth of which when propagated reverted to the original form of its parent stock. Heinrich Schultheis, a Hybrid Perpetual rose of deep, rosy pink, sported with Paul & Sons, of London, and produced Paul's Early. Blush, a light silvery pink. Again it sported with Alex. Dickson & Sons, in Ireland, and produced another silvery pink, known as Mrs. Harkness. Both of these new roses were perpetuated and became quite popular before the Hybrid Teas came into general notice. In the year 1913 Dr. Robert Huey, of Philadelphia, still had plants of Paul's Early Blush and Mrs. Harkness. It was remarkable that specimens of both these plants partially reverted to the old form of Heinrich Schultheis, throwing up shoots with rose colored blooms.
While sports are of rare occurrence, nevertheless it would well repay all rose lovers to watch for such breaks, as valuable novelties may thereby be secured which otherwise would be lost.
Seedlings, as the name signifies, come from seeds hybridized either by chance or by man's handiwork. Nearly all the older rose growers gathered their heps containing the seeds in the autumn of each year and planted great numbers of these in nursery rows, hoping to secure new varieties; in this manner a great many of the Hybrid Perpetuals were discovered and introduced. However, of late years the commercial rose growers of Europe have hybridized different varieties of roses, and by careful selection and breeding for several generations are securing their new introductions.
In Europe this work is maintained on a very large scale. Thousands upon thousands of seedlings are raised each year, and only a very small percentage are of any practical use. In this country only a few men have achieved any great success in introducing new varietiesóJohn Cook, of Baltimore, Maryland; E. G. Hill, of Richmond, Indiana; M. H. Walsh, of Woods Hole, Massachusetts; Dr. Van Fleet, of Washington; W. A. Manda, of New Jersey; and the late Jackson Dawson, of the Arnold Arboretum. In the American Rose Annual only twelve men are mentioned as having introduced new varieties in this country. Cook introduced My Maryland and Radiance, and lately he has brought out Panama; and Hill has given us quite a number of good roses, the best perhaps for outdoor culture being General Mac-Arthur, which is one of the finest all-round outdoor red roses grown in America today. Walsh, Manda and Van Fleet have been particularly successful in developing new climbersóWalsh's most notable being Excelsa, Hiawatha, Sweetheart and Evangeline, all excellent additions and ranking with the best of this class.
Father George Schoener, of Portland, Oregon, is doing some very fine work, not only in new varieties of roses, but also in new stocks for budding. In addition, he is making crosses between different members of the Rosacem order. His seedlings won a silver medal at Portland in the fall of 1915. It is hoped that ere long some of his novelties will be on the market.
Following will be found a tabulated record of the breeding of the main varieties in which the Hybrid Perpetuals and Teas figure. It has not been arranged at all in conformity with the usual botanical analyses of species and sub-species, but the information given has been taken from such books as Pemberton's and placed together so that the history of the breeding of the different varieties may be seen at a glance. There are several authorities who have noted that the exact breeding of the Hybrid Perpetuals is to some extent problematical. The roses named as the Hybrid Perpetuals' immediate ancestors are generally accepted as such, but some few other varieties were used in the gradual evolution of this class from the first Hybrid Perpetual until the list was completed. At the present time there are fewer Hybrid Perpetuals bred, as the Hybrid Teas have almost entirely superseded them.
The work of hybridization is a most interesting one, but unless carried out on a scientific scale it is almost entirely a matter of chance whether or not anything of value may be secured. No doubt any one cultivating roses to a large extent would greatly enjoy trying to introduce a new variety of his own breeding.
Ordinarily to hybridize roses properly one must have a greenhouse and it is astonishing what results may be obtained in a very small one.
In exceptionally dry climates the work may be carried on successfully out-of-doors.
Books on this subject which are interesting and practical are:
"The American Rose Annual."
"Plant Breeding," L. H. Bailey.
"Plant Breeding, Experiments of Nillson and Bur-bank," De Vries.
"Plant Life and Evolution," Campbell.
"New Creations in Plant Life," Harwood. "Fundamentals of Plant Breeding," Coulter.