AN ENCYCLOPAEDIA OF HORTICULTURE. 



243 



LAYERING. Layering is a method of propagation 

 by means of which plants are rooted and increased while 

 still fed by the parent. It is a most useful plan for 

 propagating plants that do not succeed when wholly 

 detached as cuttings. Sap flows through branches by 

 the alburnum, and youngest layers of wood, to the leaves, 

 and then returns by the inner bark, forming woody matter 

 in its progress. The principle on which Layering is 

 founded, is that of causing the returning sap to form 

 roots at a certain place, of suitable texture, in the stem, 

 and so constitute a separate and independent plant, which 

 may afterwards be detached, and utilised for perpetuating 

 the species. In some cases, roots are readily emitted 

 from almost any firm portion of a branch, by merely 

 fixing it and covering with soil. Generally, however, it 

 is necessary to partially interrupt the course pursued 

 by the sap, in order to induce it to form other roots, 

 instead of returning to those of the parent plant. With 

 this principle in view, various modes of Layering are 

 practised, according to circumstances, and the sort of 

 plant under treatment. The principal methods adopted 

 are : Layering by simply Bending and Pegging the branch 

 into the earth, Tongueing or Heeling, Einging, Wiring 

 or Strangulation, Twisting, Piercing, Serpentine Arching, 

 and Insertion of the Growing Point. 



Layering by simply Bending into the earth is very easy, 

 and plants are readily propagated when it succeeds. 

 All buds should be removed from the shoot, except a 

 few near the top, which are intended for forming leaves. 

 The part covered with soil should be secured with a peg, 

 and the point bent in an upright direction, and tied to 

 a stake. 



FIG. 382. METHODS OF LAYERING. 

 A, By Tongueing or Heeling. B, By Ringing. 



Tongueing, or Heeling, is a method largely prac- 

 tised, with much success. It consists of cutting the 

 branch half-way through, below a bud, and making an 

 incision (varying in length with different plants) in an 



Layering continued. 



surfaces be kept separated by some of the soil, or another 

 substance, such as a small piece of wood ; otherwise, 

 the parts might unite again, instead of forming roots. 



Einging is a mode represented in Fig. 382, B. The Layer 

 is bent down, and secured with a peg, as in the process 

 of Tongueing; but, instead of the wood being cut, a 

 ring of bark is taken off in this case, cutting quite 

 through the outer and inner layers, in order to effec- 

 tually arrest the sap on its return. The peg should be 

 inserted near the place where the ring has been removed, 

 and the latter portion must be well covered with soil, 

 and be kept frequently moistened. 



Wiring, or Strangulation, refers to the Layering of 

 branches which have had a wire strained tightly round 

 them, so as to check the sap, and cause an accu- 

 mulation of woody matter above the wire. Eoots are 

 not readily formed on this enlarged portion, when ex- 

 posed to the air, but they usually appear when it is laid 

 in soil, sometimes very soon. Pricking the bark through 

 with a sharp instrument tends to encourage the produc- 

 tion of roots. Tongaeing and Einging are both pre- 

 ferable to this method, where their adoption proves 

 practicable. 



Twisting is the same as simply Layering in the earth, 

 excepting that the branch is twisted for the purpose 

 of rending the sap-vessels. Many plants will not bear 

 such treatment without breaking; consequently, it can 

 only be practised in certain cases. 



Piercing, like Twisting, refers to another plan of 

 ordinary Layering, and differs only in detail. The branch, 

 in this case, is pierced or punctured with some sharp 

 instrument before being pegged and covered -with soil. 

 Clean cuts are always much better than bruises, and, for 

 thia reason, the removal of a notch on the under portion 



FIG. 383. LAYERING BY TONGUEING OR HEELING. 



upward direction towards the point (see Figs. 382, A, and 

 383). In covering with earth, it is important that the cut 



FIG. 384. LAYERING BY PIERCING OR NOTCHING. 



of each layer (see Fig. 384) is, of the two, to be pre- 

 ferred. 



Serpentine Arching is a method of Layering some- 

 times adopted for propagating plants with long, firm 

 shoots. The shoot is brought to the ground and Layered 

 in several places by one of the methods previously 

 alluded to. The intervening spaces, or curves of the 

 branch, should be furnished, above ground, with growing 

 buds, so that each portion may ultimately be severed, 

 to form a separate plant. 



Layering by Insertion of the Growing Point is some- 

 times an available method, if others fail, or when roots 

 are not readily emitted. Points of firm shoots, for in- 

 stance, of scarce varieties of Currants, Gooseberries, or 

 Eubus, if placed and secured in newly-dug soil, in summer, 

 will form a quantity of roots by autumn, and will be 

 furnished with a growing bud. In such cases, this method 

 may be successfully utilised for propagating. 



Circumposition is an old term applied to the Layering 

 of plants whose branches are far from the ground, or, 

 for various reasons, will not bend. It is still practised 

 I occasionally, but not to any great extent. The branch, 

 | in most cases, is either ringed, or has an incision made 

 in it, and this part is placed inside a pot or box and sur- 

 rounded with soil. An ordinary flower-pot, cut in two 

 | before being burned, answers well, as the two parts may 



