382 VEGETABLE FORCING 
vegetables is adapted to culture under glass throughout 
the forcing period. This factor in itself is a strong 
argument in favor of growing more than one crop. It is 
not unusual, however, to find a grower, operating in a 
comparatively small establishment, growing one crop, 
often tomatoes or cucumbers, for 10 or 11 months of the 
year. 
Succession cropping is popular with a majority of 
American greenhouse growers. At least 90 per cent of 
them believe that the largest profits may be realized by 
growing either two or three crops. Lettuce is the 
favorite crop during the late fall and winter, when there 
is so much dull, cloudy weather. Tomatoes and cu- 
cumbers generally do well early in the fall, but they 
are much more successful in the spring and early sum- 
mer. 
Succession cropping plans.—The following are the 
most important succession cropping plans for the entire 
forcing season, beginning September 1 and continuing 
until August 15 of the next year: 
(1) Three or four crops of lettuce followed by cu- 
cumbers, — 
(2) Three or four crops of lettuce followed by tomatoes. 
(3) One crop of tomatoes or cucumbers, one or two 
crops of lettuce and one crop of tomatoes or cucumbers. 
Various other plans of succession cropping are less 
common. Among them may be mentioned the following: 
Lettuce, cauliflower and tomatoes or cucumbers; cauli- 
flower, radish and tomatoes or cucumbers; radish, two 
crops lettuce and tomatoes or cucumbers. 
The cool crops of minor importance, such as spinach, 
beet, carrot, cress, mint, swiss chard, etc., may be used in 
the rotation, any time during the fall, winter and early 
spring. 
Companion cropping.—Companion cropping in green- 
house culture is not so common, although used to a con- 
