192 



PRINCIPLES OF PLANT CULTURE 



Fig. 



87. — Mound-layering of 

 gooseberry plants. 



vigorous shoots, which are ridged up about midsummer 

 or preferably not until the succeeding fall or spring. The 

 ridging should be sufficiently 

 high to cover several of the 

 lower nodes (115). Roots 

 grow out at the nodes and 

 the shoots are usually well 

 rooted by the autumn fol- 

 lowing the ridging. 



Many woody plants that 

 do not readily form roots 

 when layered may be induced 

 to do so by mutilating the stem somewhat in the covered 

 part. This tends to restrict the growth current (79) and 

 causes accumulation of reserve food, from which roots 

 may grow. Girdling, twisting, bending or split- 

 ting the stem for a short distance will often have 



the desired effect (Fig. 

 88). 



Layering is a very 

 reliable and expeditious 

 method of propagating 

 many woody and her- 

 baceous plants. 



349. Propagation by 

 division of the crown 

 of the plant, which is 

 practicable with many 

 perennial herbs, as the 

 rhubarb, dahlia, globe 

 artichoke and the like, 

 though not strictly analogous to propagation by stolons 

 or layers, may be considered here. It consists in taking 



Fig. 88. — Layered branch of currant, 

 split to encourage the formation of 

 roots. 



