PLANTING. 27 



they do not perfect a sufficient quantity for the general purposes of propa- 

 gation, or are accidental varieties only of a species losing their characters 

 of distinction when reproduced from seed. The following modes of pro- 

 pagation are found effectual when seeds cannot be obtained : first by 

 suckers, second by layers, third by cuttings, and fourth by grafting. 



1st. Suckers are shoots produced by the creeping roots of a tree, which, 

 when separated from the parent root and transplanted, become perfect 

 trees. They are generally sufficiently rooted in the first season of their 

 production, and they should not be suffered to remain longer than two 

 seasons attached to the root of the tree ; for if continued longer, the sup- 

 port they derive from the parent root prevents them from making inde- 

 pendent roots of their own in such abundance as they do when separated 

 or taken up at an earlier period. The spring is the most proper season for 

 taking them from the parent roots. When a sufficient number of rootlets 

 appear on the sucker, no part of the root from whence the sucker sprang 

 should be left attached to it ; but where the proper rootlets are deficient 

 in number, a small portion of the parent root may be left with advantage. 

 The plants should be planted in rows in fresh soil, and treated iu all re- 

 spects afterwards as directed for seedling transplanted trees. The kinds 

 of trees chiefly reared in this mode are : 



The abele tree, Populus alba. 



Common white poplar, Populus canescens. 



Aspen, Populus tremula. 



Chinese ailanthus, Ailanthus glandulosa. 



The first three kinds may also be propagated by layers. 

 2nd. Layers. The process of layering is well known : it consists in bend- 

 ing a young branch (a,fig. 2) into the soil to a certain depth, and elevating 

 the top part of it out of the soil in an upright direction ; in time the buried 

 part takes root, and the shoot becomes a perfect plant. The root which 

 produces the young shoots for layering is called the stool. Stools are 

 planted about six feet apart every way in a deep fresh soil. The stem at 

 first is either bent down into the ground as a layer, or cut over a few 

 inches from the root. The shoots which are produced from its sides form 



the layers (d). The rooting of the 

 layers is much facilitated by ob- 

 structing in part the descending sap ; 

 this is essential to some kinds of 

 layers, though not to all : the com- 

 mon laurel, privet, &c., strike root 

 readily without any artificial stop- 

 page of the descending sap. The 

 most expeditious mode of effecting 

 this, is to cut a notch, slanting upwards to the origin of the layer, about 

 half a diameter in length (/), and securing the position of the layer in the 

 ground by a wooden peg (). Where the shoot is of a nature that roots 

 with difficulty, it is useful to split the tongue of the notch halfway up, and 

 to insert a small wedge of potsherd or wood to keep the division open. 

 Rings of wire are also sometimes used for the same purpose, and cutting 

 the bark round the part to within a little of the complete circumference of 

 the shoot. In all ordinary cases, however, the slit or notching mode is 

 perfectly effective. The ground should be kept quite clean of weeds, and 

 watered in dry weather. When sufficiently rooted, the layers should be 

 carefully cut away from the shoots, with all the fibrous roots attached to 

 them, and planted in rows in fresh, well-prepared soil. The stools should 

 have all the stumps of the branches cut away, and left to produce a fresh 



