8 BULLETIN 419, U. S. DEPARTMENT OF AGRICULTURE. 



not, in the aggregate; produce such disastrous results as in a large 

 one. Furthermore, the time suitable for field planting can be util- 

 ized more readily with locally grown stock. Trees raised in nurseries 

 at a lower elevation, for example, may begin vegetation before con- 

 ditions on the planting site permit setting them out, and the best time 

 for planting a warm, early site may pass before stock can be fur- 

 nished from a nursery in a colder situation. On the other hand, 

 because of the closer and more efficient supervision in the large 

 nurseries, as well as better facilities for tending the stock, a greater 

 proportion of the plants normally survive to the age of field plant- 

 ing, and the better care given the stock results in its being more 

 fully developed and, other conditions being equal, more able to suc- 

 ceed under field conditions. The concentration of the work at large 

 nurseries makes for efficient management, good stock, and low cost 

 of production. 



A central nursery should have a capacity of at least a million 

 plants. This is desirable as a matter of economy, for the larger 

 the nursery the more opportunity there will be for intensified work, 

 the systematizing of each operation, and regular supervision. By 

 these means the cost per thousand plants may be reduced; three 

 or four million seedlings can be grown at a lower cost per thousand 

 than one or two million. A large capacity is desirable for two other 

 reasons besides the economy that may be effected : It is an insurance 

 against a shortage of plants due to unforeseen losses, and heavy 

 grading is possible in well-stocked nurseries, so that in each case very 

 nearly the class of stock required may be furnished. 



The actual area of a nursery is determined by the output that is 

 desired, the species, the area occupied by paths and roads, the spac- 

 ings. the class of stock produced, and the practice followed in the 

 rotation of crops. Possible rotation of crops being disregarded, 

 the following table indicates the area, exclusive of paths and roads, 

 necessary for the growing of 1,000,000 seedlings and transplants 

 yearly. 



Table 1. — Secd-hed area 1 in square feet, iieeessari/ to produee 1,000,000 seed- 



lings yearly. 





Number of seedlings per square foot. 



Length of lime in seed 

 beds. 



50 



75 



100 



12S 



150 



175 



200 



225 



250 



275 300 





Area in square feel. 2 





1 year 



20,000 

 10,000 



GO, 000 



13,333 

 26,667 



1(1,000 



10,000 

 20,000 



:;o, ooo 



8,000 

 10,000 

 24,000 



0, 667 

 13,334 



20, 000 



5,714 

 11,428 

 17,142 



5,000 

 10,000 

 15,000 



4,444 



8, SSS 

 13,332 



4,000 

 8,000 

 12,000 



3, 636 



7 272 

 10,' 008 



3,333 

 6,666 





10.000 











1 Add 2. r > per cent in seed beds and from 10 to 20 per pent in transplant beds to allow 

 for losses. 



2 1 acre=4.'5,. r >00 square feet. 



