We have seen that Rhododendrons are generally grafted, but in common with many other shrubs garden varieties may be propagated by layers. A low-growing branch of one-year or two-year-old wood is convenient, as it can be pegged down to the soil without any trouble. It is best to cut a notch out of the shoot half way through near a joint, peg the branch down so that the cut part is embedded in the soil, and leave it for a year - two years if roots have not formed before. The soil should be light and friable. As we see above, Magnolias may also be increased in this way, but they are rather slow in rooting.
Layering may be done in the late summer or autumn, when the ground is warm and moist.
The following plants may be layered:
Propagation by division is not common, as shrubs and trees generally have not the habit of growth which makes this method appropriate. It will be found, however, that some shrubs, notably some of the Spiraeas, form growths in the border, and these can be taken and planted. Berberis Aquifolium has a dense, tufted habit and may also be divided. Some Heaths which have a tufted habit may be divided. The work is best done just when growth starts in spring. List:
Spiraea (and suckers).
Symphoricarpus (suckers) Yucca.