122 



THE BOOK OF NATURE STUDY 



The cuttings are taken in March, planted at a distance of one 

 foot from each other, and well watered. 



PROPAGATION BY DIVISION. This is a very simple operation. 

 Experience shows that the smaller perennial herbaceous and 



woody flowering plants are at their 

 best during the first three or four years 

 after planting. At the end of that 

 time the plant usually deteriorates 

 from a horticultural point of view. 

 It will have become straggling and 

 " leggy/' and the proportion of flowers 

 to the size of the plant will have de- 

 creased. Part of this effect is due to 

 the natural growth of the plant, and 

 part to exhaustion of the available 

 mineral matter in the soil. In these 



FIG. 56.- Lifting and Dividing . . . 



Clumps. Roots A, A are not circumstances it is desirable to transfer 

 broken when a fork is used; the plant to another position, and at 





several portions, each of which may 

 be separately planted. The original plant is dug up with a fork, 

 and it will then be found that adventitious roots will have been 

 produced on the underground portions of most of the shoots. 

 These may be torn apart with one's hands, the coarser shoots 

 being discarded and the younger ones trimmed and replanted, 

 care being of course taken that each shoot selected for replanting 

 bears some roots. Propagation by division should be carried out 

 in October, when the plant is entering upon its resting stage. 



LAYERING. This is an operation intermediate between 

 propagation by cuttings and propagation by division. In the 

 former case adventitious roots are developed after the cutting 

 is taken ; in the latter case, before the separation from the parent 

 plant. In layering we induce the formation of adventitious 

 roots in a shoot by partially severing the shoot from the parent. 

 The essence of the method consists in cutting partly through a 

 shoot, just below a node, and then bending the shoot down, 



