GROWING PLANTS FROM CUTTINGS 65 



The contrasting conditions and agencies may be expressed in this way : 



DORMANT TISSUE ACTIVE TISSUE 



Less moisture More moisture 



Less heat Higher heat 



Slower start in growth Rapid start in growth 



Although this contrast is warranted to emphasize general relations, it 

 should also be stated that greater moisture and higher heat are used to 

 hasten activity of dormant tissue also, when that is necessary or desirable. 



How these agencies are brought to bear in propagation will be noted in 

 the following discussion of materials and methods: 



GROWTH OF PLANTS FROM CUTTINGS. 



Cuttings are severed portions of any part of a plant leaf, twig, branch, 

 stem or root which experience has shown to be desirable. These words 

 are used in designating their source and they are also even more specifically 

 localized by the use of such words as "tip," "base," "terminal," "lateral," 

 etc. Such words may be encountered in discussions of particular plants in 

 subsequent chapters. The unqualified word "cutting" is intended to desig- 

 nate an serial part of the plant, and to have a more or less woody character. 

 From this point of view cuttings may be divided into two classes, viz. : 



Hard Wood Cuttings Which are usually mature, dormant, and taken 

 from deciduous plants, or from some evergreens during their brief periods 

 of lessened activity. 



Soft Wood Cuttings Which are usually immature, more or less inac- 

 tive growth, herbaceous, and are taken from either deciduous or evergreen 

 plants during their active growth. 



Obviously both kinds of cuttings can be taken from many plants at 

 different times of the year. Obviously, also, strictly herbaceous plants 

 never afford any hard-wood cuttings, but many of them grow so readily 

 from soft-wood or herbaceous cuttings that nothing more than open-ground 

 treatment is required for them. This is a fact which, much to their disad- 

 vantage, many beginners do not know. 



Length of Cuttings. As a single bud possesses the potentiality of 

 a plant, a cutting or a severed-part taken for making a younger plant need 

 only consist of one bud and its adjacent tissue from which roots may 

 strike. But in operating with such a small fragment there is such imminent 

 danger of drying out that single-bud cuttings are seldom used, except when 

 the variety is exceedingly rare and the reason for rapid multiplication 

 imperative. In' such a case it is possible to make plants from single 

 dormant "eyes" or buds by increasing heat and securing humid atmosphere 

 as well as adequately moist soil, and these must, in nearly all cases prob- 

 ably, be artificially produced. 



