188 LAYERS. LEAVES. 



perfume, is distilled from the flowers ; for which purpose the 

 plant is extensively cultivated in different places." London. 



LAYERS. Layers, in horticulture, denote certain ten- 

 der shoots or sprigs of trees, which are buried in the ground 

 till they have taken root, when they are separated from 

 the parent stock, and become distinct plants. The opera- 

 tion of layering should be commenced before the ascent ol 

 the sap, or delayed till the sap is fully up, to wit, early in 

 spring, or in mid-summer. The shoot intended to be- 

 come a new plant, is half separated from the parent plant, 

 at a few inches from its extremity. If the cut or notch 

 does not penetrate at least half way through, some sorts of 

 trees will not form a nucleus the first season ; on the other 

 hand, if the notch be cut nearly through the shoot, a suffi- 

 ciency of alburnum, or sap-wood, is not left for the ascent 

 of the sap, and the shoot dies. In delicate sorts, it is not 

 sufficient to cut a notch merely, because, in that case, the 

 descending sap, instead of throwing out granulated matter, 

 in the upper side of the wound, would descend by the entire 

 side of the shoot ; therefore, besides a notch formed by cut- 

 ting out a portion of bark and wood, the notched side is slit 

 up at least one inch, separating it by a bit of twig, or small 

 splinter of stone or potsherd. 



Mr. Armstrong says, (Mem. of N. Y. Board of Agr. vol. 

 iii. p. 15,) " This mode was probably suggested by observ- 

 ing the habits peculiar to some trees and shrubs, (as the 

 laurel and the currant,) of pointing their branches to the 

 earth ; where,- finding an habitual moisture, they strike 

 root, and become distinct plants. In imitating this natural 

 process, the artist notches the lower side of the branch, 

 buries this in the earth, three or four inches deep, and 

 keeps it down by a wooden crotchet. As this is done 

 before the descent of the sap, the notch operates like a dam 

 or obstruction to the descending juices, and forces them 

 into a bulbous form, and granular substance, whence are 

 emitted a mass of roots, necessary to the infant plant. When 

 these are sufficiently formed, that part of the branch which 

 binds them to the stem is severed, and the layer taken up 

 and transplanted." For further particulars respecting the 

 manipulation, &c., in this mode of propagation, see Encyc. 

 of Gardening, pp. 388, 389. 



LEAVES. The leaves of trees, particularly of oak, may 

 be employed ad; mtageously to form hot-beds. Speedily, 

 an eminent English gardener, gives the following account 

 of his mode of using them : 



