PROPAGATION BY LAYERS AND RUNNERS 73 



layer also possesses the advantage cf giving more than one 

 plant, but the roots are likely to form so continuously that 

 definite and strong plants are rarely obtained; these rooted 

 parts may be severed and treated as cuttings, however, with 



V' 



FIG. 63. Carnation layer. 



good results. The grape is sometimes propagated by serpen- 

 tine layering. 



Stiff and hard-wooded plants do not often "strike" or root 

 readily, and to facilitate rooting, the branch is wounded at 

 the point where it is desired that roots shall form. This wound- 

 ing serves to induce formation of adventitious buds at that 

 point, and to check the growth of the branch at the tip. It is a 

 common practice to cut the branch about half in two, obliquely 

 on the lower side. This operation is known as "tongueing." 

 Twisting, notching, "ringing" or girdling, and various other 

 methods are employed, none of which, perhaps, possesses any 

 peculiar advantages in general practice. Some propagators 

 cut all the buds from the covered part. In this case the free 

 and protruding end of the layer is expected to form the top of 



