186 VEGETABLE FORCING 



prolonged until February 26, 1897. The bed was 25 by 75 feet, or 

 equivalent to a row 450 feet long. It produced 234 market bunches 

 besides considerable that was taken for exhibition purposes. 



"At this writing, May 2, 1898, the spring growth of asparagus 

 from the beds forced during the winter of 1896-97 shows that one 

 season's growth, after forcing is sufficient for the plants to regain 

 their normal vigor. 



"By blowing steam directly into the tunnels the soil is kept moist; 

 the steam has a penetrating effect, and permeates all parts of the 

 bed, giving a uniform heat throughout; this moist steam keeps up 

 a continual fermentation of the manure mulch, thus giving heat 

 and only occasional brief steamings are necessary. 



"Care must be taken not to use too much steam at one time, or 

 the plants may be ruined by over-heating. Our asparagus rows 

 were 4 feet part, the tunnels midway between them were only 8 

 inches wide, and yet we found that five minutes at a time was as 

 long as was safe to force steam into a single tunnel. 



"These experiments have been so successful as to indicate that 

 anyone provided with a steam heating plant, could successfully 

 force asparagus for the markets in this manner." 



Ordinary drain tiles were also used at the Missouri Ex- 

 periment Station, but they did not give satisfactory re- 

 sults. Cornell Station forced asparagus in a portable 

 pipe-frame house covered with canvas. It was 20 by 50 

 feet in size. The sides or walls were 18 inches high and 

 the frame consisted of a ridge and three pairs of rafters. 

 With five lines of steam pipe, one under the ridge and 

 two at each side of the house, no difficulty was experi- 

 enced in forcing asparagus during the winter months. 

 At the close of the forcing period, the canvas is removed 

 and the beds are cultivated for a season, and they may 

 then be used again for forcing. 



Forcing transplanted roots. Roots may be removed 

 from the field beds and forced wherever suitable condi- 

 tions can be provided. Perhaps the most common plan 

 is to use the space under greenhouse benches for this 

 purpose. Side boards may be placed along the walks to 

 retain the soil, or, if preferred, shallow trenches may be 

 dug to receive the roots. 



