This mode of propagation, although possible with all roses, is more difficult with those that bloom only once in the season. It is most applicable to the smooth-wooded kinds, as the Bengal and its sub-classes, and the Boursault, Microphylla, rubifolia, etc. Many of the Perpetuals and Bourbons are propagated with facility by the same mode. For propagation in the open ground, cuttings should be made in the autumn, or early part of winter. They should be made of wood of the growth of the season, and about six inches long. The lower end should be cut square, close to a bud, and they can then be planted thickly, two-thirds of their length in sand, in a light and dry cellar. Here a callus will be formed on the bottom of each cutting during the winter, and on being planted out in the spring, they will immediately throw out roots. They should be planted as early as possible in the spring, in a light sandy loam, with one-third of their length and at least one bud above the surface of the ground. They should be planted very early in the spring, because, if left until late, the power of the sun is too much for them. The earth should be trodden down very tight about them, in order, as much as possible, to exclude the air. If the weather is dry, they should be carefully watered in the evening. Where it is inconvenient to make the cuttings in the fall or early in the winter, they can be made in the spring; but in consequence of having to form the callus, they will require a much lighter soil than will afterward be desirable for their growth, and they will also be much[Pg 114] later in coming on. This mode of open propagation answers very well for some of the smooth-wooded roses of the more robust growing varieties, like the Boursault and Rubifolia; but for the delicate Bengals, the best mode is pot propagation. For this purpose, small pots can be used, filled with equal parts of mould and sand, or peat and sand. About the middle of autumn, cuttings of the same season’s growth are taken off with two to four buds, cutting off one or two of the lower leaves, and cutting off the wood smooth and square close to the eye, as in figure 8. These cuttings can be inserted in the pot, leaving one eye above the surface. It should then be slightly watered to settle the soil firmly around the cuttings, and then placed in a cold frame, or on the floor of a vinery, in which no fire is kept during winter. Early in the spring the pot should be placed in a house with a moderate temperature, kept perfectly close, and sprinkled every morning with water a little tepid. Now, as well as during the autumn, they should be shaded from the too bright glare of the sun. In about a fortnight, and after they have formed a third set of leaves and good roots, a little air can be given them; and after being thus hardened for a week, they can be repotted into larger pots. In order to ascertain when they are sufficiently rooted, the ball of earth can be taken out of the pot, by striking its inverted edge lightly against some body, at the same time sustaining the ball of earth[Pg 115] by the hand, the cutting being passed between two of the fingers a little separated. If well rooted, the fibres will be seen on the outside of the ball of earth. They can then be placed in a cold frame, or anywhere under glass, to be planted out the latter part of spring, or retained for pot culture. Where hot-bed frames are not convenient, or the amateur wishes only to experiment with one or two cuttings, he can use a tumbler, or any kind of close glass covering.
Fig. 8.—A ROSE CUTTING.
Where roses are forced into bloom the latter part of winter, cuttings can be taken from them immediately after the bloom is past; and they will also succeed if taken from plants in the open ground immediately after their first bloom. Cuttings of the Everblooming Roses will all strike at any time during the summer, but they succeed much better either in the autumn, or after their first bloom. The heat of our midsummer sun is so great upon plants forced in the house, that cuttings often fail at that time. When a cutting is made near the old stem, it is better to take with it a portion of the old wood, which forms the enlarged part of the young branch. Where the cuttings are scarce, two buds will answer very well—one below the surface; and, in some cases, propagation has been successful with only one eye. In this case they are planted up to the base of the leaf in pots of sand, similar to that used in the manufacture of glass, and the eye is partially covered. They are then subject to the same treatment as the others, and carefully shaded; they will thus root easily, but require a long time to make strong plants.
Some years since, Lecoq, a French cultivator, conceived the idea of endeavoring to propagate roses by the leaf. He gathered some very young leaves of the Bengal rose, about one quarter developed, cutting them off at their insertion, or at the surface of the bark. He planted these in peat soil, in one-inch pots, and then plunged the pots[Pg 116] into a moderate heat. A double cover of bell glasses was then placed over them, to exclude the air entirely, which course of treatment was pursued until they had taken root. The shortest time in which this could be accomplished was eight weeks, and the roots were formed in the following manner. First, a callus was formed at the base of the leaf, from which small fibres put forth; a small bud then appeared on the upper side (figure 9); a stalk then arose from this bud, which finally expanded into leaves and formed a perfect plant.
Fig. 9.—LEAF CUTTING.
An English writer remarks, that “the leaves or leaflets of a rose will often take root more freely than even cuttings, and in a much shorter time, but these uniformly refuse to make buds or grow.”
This experiment is certainly very curious, and evinces how great, in the vegetable kingdom, are the powers of nature for the maintenance of existence, and is one of those singular results which should lead us to make farther experiments with various parts of plants, and teach us that in Horticulture there is yet a wide field for scientific research.
A favorite mode of propagation with some nurserymen is from soft wood of plants forced in the winter. Many fail entirely in this for want of knowledge of the right condition in which the wood should be before cutting, a condition which cannot be described on paper. Some varieties, like Persian Yellow, will not strike at all, or with great difficulty in this way.
The plants from which these cuttings are to be taken should be prepared and treated as in the preceding chapter. In February and March the cuttings are made and inserted in sand, either in pots or benches, in a house of[Pg 117] the same temperature as that in which the parent plant has grown. These pots or benches would be better covered with glass, but it is not essential. After the cuttings have rooted, they can be potted into small pots, and placed in a house of moderate temperature. About the middle of May they can be taken out of these pots and planted in the open ground.
BY LAYERS.
This mode is more particularly applicable to those roses that bloom only once in the year, and which do not strike freely from cuttings, although it can be equally well applied to all the smooth-wooded kinds. It can be performed at midsummer and for several weeks afterward, and should be employed only in those cases where young shoots have been formed at least a foot long and are well matured. The soil should be well dug around the plant, forming a little raised bed of some three feet in diameter, with the soil well pulverized and mixed with some manure thoroughly decomposed, and, if heavy, a little sand. A hole should then be made in this bed about four inches deep, and the young matured shoot bent down into it, keeping the top of the shoot some three or four inches above the surface of the ground; the angle thus being found, which should always be made at a bud and about five or six inches from the top of the shoot, the operator should cut off all the leaves below the ground. A sharp knife should then be placed just below a bud, about three inches below the surface of the ground, and a slanting cut made upward and lengthwise, about half through the branch, forming a sort of tongue from one to two inches long, on the back part of the shoot right opposite the bud; a chip or some of the soil can be placed in the slit, to prevent it from closing, and the shoot can then be carefully laid in the hole, and pegged down at a point some two[Pg 118] inches below the cut, keeping, at the same time, the top of the shoot some three or four inches out of the ground, and making it fast to a small stake, to keep it upright. Care should be taken not to make the angle where the branch is pegged at the cut, as the branch would be injured and perhaps broken off; the best place is about two inches below the incision. The soil can then be replaced in the hole, and where it is convenient covered with some moss or litter of any kind. This will protect the soil from the sun and keep it moist, and will materially aid the formation of new roots. These are formed in the same manner as in cuttings; first a callus is produced on those parts of the incision where the bark joins the wood, and from this callus spring the roots, which, in some cases, will have grown sufficiently for the layers to be taken from the parent plant the latter part of the following autumn; in some cases, however, the roots will not have sufficiently formed to allow them to be taken up before another year. The summer is the best period for layering the young shoots. Early in the spring, layers can be made with the wood formed the previous year. Where it is more convenient, a shoot can be rooted by making the incision as above, and introducing it into a quart pot with the bottom partly broken out. This pot can be plunged in the ground, or if the branch is from a standard, it can be raised on a rough platform. In either case, it should be covered with moss, to protect it from the sun, and should be watered every evening. We recollect seeing in the glass manufactories of Paris, a very neat little glass tumbler, used by the French gardeners for this purpose. It held, perhaps, half a pint, and a space about half an inch wide was cut out through the whole length of the side, through which space the branch of any plant was inserted, and the tumbler then filled with soil. When the roots were formed and began to penetrate the soil, they could be easily perceived through the glass.[Pg 119] Although an incision is always the most certain, and it is uniformly practiced, roots will in many varieties strike easily from the buds; and a common operation in France is simply to peg down the branches in the soil, without any incision; in some cases, they give the branch a sudden twist, which will break or bruise the bark, and facilitate the formation of roots.
Some Chinese authors state that very long branches may be laid down, and that roots may be thus obtained from all the eyes upon them, which will eventually form as many plants.
Vibert, a well-known rose cultivator in France, remarks upon this point: “Upon laying down with the requisite care some branches fifteen to twenty-four inches long, of the new growth, or of that of the previous year, and upon taking them up with similar care, after twelve or eighteen months, I found only the first eyes expanded into buds or roots, while the rest had perished. I have seldom seen the fifth eye developed, while I have frequently known the whole branch entirely perish. I speak in general terms, for there are some rare exceptions, and the different varieties of the Four-seasons Rose may be cited as proof that a great number of eyes of the same branch have taken root.”
This is the opinion of an eminent rose grower; but if, as he states, the Monthly Damask Rose will root freely in this way, many of the smooth-wooded roses would undoubtedly root still more readily, and our rapid growing native rose, Queen of the Prairies, would very probably throw out roots readily, when treated in this manner. It is worth repeated experiment; for, if rapid growing roses, like some of the evergreen varieties, the Greville, and the Queen of the Prairies, could with facility be made to grow in this way, rose hedges could be easily formed by laying down whole branches, and a very beautiful and effective[Pg 120] protection would be thus produced, to ornament our fields and gardens.
SUCKERS.
Many roses throw up suckers readily from the root, and often form one of the principal causes of annoyance to the cultivator. For this reason, budding and grafting should always be done on stocks that do not incline to sucker. The Dog Rose—on which almost all the imported varieties are now worked—is particularly liable to this objection, and it is no unusual thing to see half-a-dozen suckers growing about a single rose-tree. When the health and prosperity of the plant are desired, these should be carefully kept down, as they deprive the plant of a material portion of its nourishment. When, however, they are wanted for stocks, they should be taken off every spring with a small portion of root, which can generally be obtained by cutting some distance below the surface of the ground. They should be planted immediately where they are wanted for budding, and will soon be fit for use. Many fine varieties of the summer roses will sucker in this way, and an old plant when taken up will sometimes furnish a large number of thrifty stems, each with a portion of root attached.
BUDDING.
Fifty years ago, budding and grafting were very little practiced, excepting with new v............