PTNE-APPLE — BIENNIAL COURSE. 3|3 



air should be admitted, and the plants ought to be set 

 widely, that they may have room to swell below, and 

 become stout and bushy. 



Bienyiial Course. — The method of culture which we 

 have denominated the biennial course was first brought 

 into notice by Abercrombie, and more recently has been 

 strenuously recommended by Baldwin. Its chief feature 

 is the acceleration of the growth of the plants by the 

 application of higher temperatures than it wa& formerly 

 supposed they would flourish in. They are, in fact, 

 made to attain the growth of two summers in the course 

 of one yeai'. 



About the. beginning of Marph,- the most forward of 

 the plants potted over winter, or the suckers kept iiv tan, 

 are taken out, the earth or tan taken away, and the roots 

 shortened. Tljey -are then put into pots^about five 

 inches in diameter, which are plunged into frames or 

 pits heated with tan or stable-litter. They are shaded 

 as usual, and, after they begin to grow, receive moderate 

 waterings. When the roots appear around the balls of 

 soil, which will be about the middle of June, tlie plants 

 are again shifted into larger pots from six to sevpn 

 inches in diameter, and, if the heat be declining, are re- 

 moved into other- pits or beds. In the beginning of 

 August they are transferred into large pots, in which, 

 unless they are intended^ for early spring forcing, they 

 stand during the winter ; and in February they are 

 finally shifted into pots twelve or fourteen inches in dia- 

 meter. For spring forcing, "the last shifting takes place 

 in October, and the pots may be two inches narrower. 

 At every shifting the ball <)f earth is preserved entire. 

 From March the temperature is gradually increased ; 

 little air is admitted, even in strong sunshine, and a 



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