196 VEGETABLE FORCING 
side of a greenhouse or other building. Economy in con- 
struction and heating is important. Paper roofs will be 
satisfactory and second-grade lumber may be used for 
the walls. Small windows should be well distributed in 
order that all parts of the house may be equally lighted. 
Such houses are sometimes used for the storage of celery 
and root crops until Thanksgiving or later, and the rhu- 
barb may be planted any time after this, though it is 
seldom forced before January 1. 
oS one , 
Fig. 65.—An inexpensive rhubarb house near Boston. Sash are placed on the 
frame whenever it is desired to force the crop. 
Varieties.—Several varieties, such as Linnezus, Straw- 
berry, Victoria, Paragon and Mammoth, are mentioned 
in connection with the forcing of rhubarb. Varietal dis- 
tinctions are not marked or well defined, so that it is 
impossible to give specific information on this subject. 
The Linnzus type is earlier and smaller than the Vic- 
toria, which seems to be regarded as the most vigorous 
of the varieties, excepting, perhaps, the Mammoth. Both 
Linneus and Victoria are extensively used for forcing. 
There is so much variation, however, in strains of differ- 
ent varieties that the whole matter is in a state of con- 
