Propagating By Leaf Cuttings

Press, Volume CVI, Issue 31327, 25 March 1967, Page 17

Propagating By Leaf Cuttings

Various ways of plant propagation have been described from time to time. One method which has not been previously dealt with is that of propagating by means of leaf cuttings. This method is restricted to a small group, many of which are common house plants.

Leaf cuttings can be taken and rooted at any time of the year, but best results are obtained from those taken in spring and summer when the leaves are young and temperatures relatively high. There are three forms of taking these cuttings. They are:—

(1) From leaf serrations, which produce bulbils which root. Kalanchoe, Biyaphyllum and Asplenium bulbiliferuxn are examples which can be done in this way. These can be taken all the year round, but best results are generally achieved in spring. (2) Use of the complete leaf which can be used several times although a higher percentage of loss is likely as there is progressively less nourishment available from the leaf. Saintpaulaia, gloxinias and streptocarpus can be propagated in this way. (3) Leaf segments. Sanseviera is a common example where this method is employod Three fairly widely grown plants have been selected to describe various methods of propagation by leaf cuttings.

Begonia rex.—The large mature leaves are detached from the parent plant with a portion of leaf stalk, and cuts are made through the main veins on the underside of the leaf. A box is partially filled with sandy soil and on top of this is spread a layer of coarse sand. The leaf stalk is inserted into the soil to give the necessary support and small stones or pins are placed on the leaf to hold the under surface in contact with the sand. The upper surface is lift exposed and not covered. The box is kept in a warm moist and humid place but protected from the direct rays of the sun. Young plants will begin to develop from each cut, usually two from each slit, and can be detached and potted after about eight to 10 weeks. An alternative method is to cut large triangular shaped sections of leaf, each with a piece of large vein attached, and insert into sand, point down. New plants develop from the base. Saintpaulala ioantha (African violet). The leaf is detached with a portion of leaf stalk. A pot is filled with sandy soil and then covered with a layer of pure sand: the cuttings are inserted into this around the edge of the pot which is then kept in a warm shady place. Water must be kept off the leaves. Roots will form quickly but at least six weeks usually elapse before a young plant can be seen. When this reaches sufficient size the plant can be potted.

Sauseviera trifasclata (Mother-in-law’s tongue). An entire leaf is detached and cut into pieces of 2in to 3in in length. The basal cut may be sloped while the upper cut is straight so as to ensure that the cutting is always upright. The leaf pieces are inserted into containers of pure sand which should be placed in a warm position either in full sun or shade. Rooting takes at least six weeks and the formation of the young plants even longer. It emerges from the base of the cutting at right angles to it and may prow like that for two or more inches before turning and emerging in the normal manner.

Sometimes it becomes necessary to use yet another method, for instance when stock is scarce or where species initiate roots but not shoots from detached leaves. It consists of the leaf blade, petiole and a short piece of stem with attached axillary bud and should only be made from well developed buds and healthy leaves. The cutting should be made with a very sharp knife and 1.8. A, or similar rooting hormone, applied, care being taken not to use too much. The leaf cutting is then placed in sand, with the bud half an inch below the surface. Keep in a place of high humidity and with bottom heat if possible for quicker rooting. Most herbaceous greenhouse plants, blackberry, lemon, camellia, rhododendron and tropical shrubs lend themselves to this method and also apple rootstocks.