In a favorable season, most of the layers will be well rooted before the frost sets in. If the weather is very dry, there will be many failures. Instead of roots, a hard cellular substance will form in a ball around the tongue. In the dry summer of 1864, the rose-layers were thus "clubbed" with lumps often as large as a hen's egg; but cases like this are rare.
In November, it is better in our severe climate to take up the rooted layers, and keep them during winter in a "cold frame;" that is, a frame constructed like that of a hot-bed, without the heat. Here they should be set closely in light soil to the depth of at least six inches, and covered with boards and matting; or they may be potted in small pots, and placed in a frame or cellar.
Layers may be made in spring from wood of the last season's growth; but laying the young wood during slimmer, as described above, is much to be preferred.
All roses may be propagated by cuttings; but some kinds strike root much more readily than others. The hard-wooded roses, including the entire family of the Hardy June roses, and especially the Mosses, are increased with difficulty by cuttings. The Hybrid Perpétuais root more readily; while the tender ever-blooming roses, including the Teas, Noisettes, and Chinas, are propagated in this way with great ease.
Cuttings may be made from the ripened or the half-ripened wood. In the case of roses, and of nearly all ligneous plants, cuttings made from the ripe wood do not require bottom-heat, and are more likely to be injured than benefited by it. On the other hand, cuttings of the soft or unripe wood strike root with more quickness and certainty if stimulated by the application of a gentle heat from below.
In propagating roses from the ripe wood, the cuttings must be made early in autumn from wood of the same season's growth. The chances of success will be increased if they are taken off close to the old wood with what is called a "heel;" that is, with a very small portion of the old wood attached. The heel should be trimmed smooth with a sharp knife: the cuttings may be six or eight inches long. Strip off any leaves which may still adhere to them, and plant them in rows, at a depth of about five inches, in a cold frame. The soil should be very light, and thoroughly drained: water it, to settle it, around the cuttings. On the approach of frost, they should be protected with boards and mats, giving them air on fine days during winter. In the spring, a white cellular growth called a "callus" will have formed at the heel of each cutting, which, if the process succeeds, will soon emit roots, and become a plant.