ASEXUAL PROPAGATION OF PLANTS ON OWN ROOTS 61 



just moist enough to prevent their drying out and, as a rule, 

 should be kept at a low temperature (just a little above the 

 freezing point) in order to keep the buds from starting. Stor- 

 ing over winter gives opportunity for the callus to form and 

 sometimes for the roots to start by planting time in the spring 

 so that the stored cutting is ahead of the spring cutting. 



Sometimes, especially with hardwood cuttings difficult to 

 root, bundles of them are buried with their base ends upward 

 just beneath the ground on a well-drained knoll. This is 

 usually done a few weeks before they are to be set out in the 

 spring. The sunshine warms the upper surface of the soil, 

 and callusing is greatly aided, while the tops of the cuttings 

 are down in the cooler portions of the soil and the buds are 

 kept from starting. It will be seen that this method is simply 

 a means of securing bottom heat. 



89. How to make hardwood cuttings. Wood of the pre- 

 vious season's growth is used in making hardwood cuttings. 

 The usual and convenient length for these cut- 

 tings is from six to ten inches. The cut at 

 the base end is usually made just below or 

 through a bud because a maximum supply of 

 food is stored at that point, and, therefore, 

 callusing takes* place readily. The upper end 

 is cut about half an inch above a bud. It is 

 customary to include two nodes in each cut- 

 ting, but with some plants, such as many varie- 

 ties of grapes, a three-node cutting gives best 

 results. When cutting wood is scarce or the FIG. 36. -Single- 

 nodes are so far apart that it is inconvenient to thl Spe! g 

 have two nodes, it is possible to make single-eye 

 cuttings, as illustrated in Fig. 36. Single-eye cuttings are 

 usually placed horizontally in sand with the bud uppermost, 

 and are covered to a depth of a little less than an inch. 



In planting hardwood cuttings in the spring, it is convenient 

 to dig a trench and set up the cuttings in it from four to six 



