CHAPTER XIV 
LETTUCE 
Most of the forced lettuce sold in the city markets 
previous to 1888 was grown almost exclusively in hot- 
beds and coldframes. About this time greenhouse con- 
struction became active, and the development of the 
industry has surpassed the expectations of the most opti- 
mistic of the pioneer growers. W.W. Rawson of Boston, 
Mass., was the most conspicuous of the eastern 
horticulturists who were producing head lettuce in green- 
houses for a number of years previous to 1890. Eugene 
Davis of Grand Rapids, Mich., is the pioneer western 
grower. He added to his range from year to year until 
he was one of the most extensive growers in the West. 
He is the originator of the Grand Rapids lettuce, and this 
accomplishment has won for him the distinction which he 
so well deserves, for it is practically the only variety 
grown in greenhouses from central Pennsylvania west- 
ward. The history of lettuce forcing in the United States 
has been closely associated with the growing of other 
crops under glass, particularly cucumbers and tomatoes. 
See Chapter I. 
Importance.—Lettuce is unquestionably our most im- 
portant vegetable forcing crop. It is seldom that a large 
commercial establishment attempts the forcing of other 
crops without planting lettuce at some period during the 
season. In hundreds of ranges the usual custom is to 
plant lettuce in the fall and continue its culture until the 
winter is well advanced, and then to grow tomatoes or 
cucumbers when weather conditions are more favorable. 
Profits can generally be realized from lettuce throughout 
the forcing season, but this cannot be said of either the 
tomato or cucumber, except when growers are unusually 
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