270 



PLANT PROPAGATION 



366. Digging stock may be done at any time the ground 

 can be worked after the leaves fall and before the buds 

 swell in spring, except when the temperature is below 

 freezing. In a small way nursery spades may be used to 

 lift individual trees. On a larger scale a furrow may be 

 thrown away from the trees on each side of the rows 

 and then spades used. In big commercial nurseries the 

 tree digger (Fig. 152) is drawn by horses (Fig. 213) or by 

 wire cables attached to drums operated by steam or gaso- 



FIG. 208— MODERN METHOD OF DIGGING NURSERY STOCK 



The el cables wound on the drums by the engine draw the digger from 

 end to end of the nursery rows. 



line engines. Nursery spades of steel and wood and 

 costing several dollars each, and made strong enough 

 to stand heavy strains, are generally worked in pairs or 

 threes (Fig. 207) around and a foot or more from the bases 

 of the trees. The blades, at least 15 inches long, are 

 thrust full depth in the soil under the trees, which are 

 lifted by leverage, care being taken to cut or break the 

 roots as little as possible. 



367. Nursery soils and their care. — Best nursery stock 

 is usually produced on heavy soils, those in which clay 

 rather than sand predominates. Of course, if level, so 



