PROPAGATION BY MEANS OF CUTTINGS 



87 



Bottom heat 



Soil somewhat warmer than the air is essential to the best 

 success with cuttings. Bottom or root growth should precede 

 top growth, and this is aided by bottom heat. This heat may 

 be two or three degrees, or three or four times that much, 

 higher than the temperature of the atmosphere. 



In outdoor work, this heat is supplied by the natural warmth 

 of the soil in spring and summer, and it is often intensified by 



FIG. 88. Nurseryman's frames in a yard, protected by muslin canopies. 



burying hard-wooded cuttings bottom end up for a time before 

 planting them, although there may be other reasons and benefits 

 in the inversion of cuttings. This inverting of cuttings is 

 often practiced with grapes, particularly with the Delaware 

 and others that root with some difficulty. The cuttings are 

 tied in bundles and buried in a sandy place, with the tops down, 

 the butts being covered 2 or 3 inches with sand. They 

 may be put in this position in autumn and allowed to remain 

 until the ground begins to freeze hard, or they may be buried 

 in spring and allowed to remain until May or June and then 



