158 AGRICULTURAL BOTANY 



must be taken to cool off the hotbed, in order that the slips may not 

 be destroyed. 



Ringing. Sometimes cuttings set out in the ordi- 

 nary way are slow in forming roots. If it is known that 

 any species is thus slow, a good remedy is to ring the 

 branches from which cuttings are to be made ; that is, 

 make a slight groove around the stem just below a 

 node, in July or August. This will induce the storage 

 of food above the groove and the formation of a callus 

 on the upper side of the ring. In the fall the cutting 

 should be made just below the ring, and the slip set 

 out in the ordinary way. 



Root Cuttings. Short cuttings, from one to three 

 inches, may be made successfully from the roots of some 

 hardy plants, like red raspberry, plum, and blackberry, 

 if made in autumn and stored in boxes with moist sand. 

 In general they thrive better if kept in a cool place, but 

 sometimes they need a little higher temperature towards 

 spring to induce the formation of roots and buds. They 

 require very shallow planting, from one half to three 

 quarters of an inch, in finely crumbled soil. Sometimes 

 they need shading and watering during early growth, 

 that is, if the weather is warm and dry. 



Layering. By layering is meant the bringing of a 

 branch into contact with the soil, covering it slightly, 

 thus inducing it to form roots and shoots which con- 

 stitute an independent plant, the branch meanwhile 

 remaining connected with the parent plant. This 

 method of propagation is often used with woody plants 

 which do not root readily from cuttings. Grape 

 vines may be stretched along the ground and buried in 

 a shallow trench or may simply be covered at certain 

 intervals : in either case roots will be sent down and 



