BULLETIN 224] [SEPTEMBER, 1914 



Ontario Department of Agriculture 



VEGETABLE GROWERS' ASSOCIATION 



Greenhouse Construction 



By S. C. JOHNSTON, B.S.A 



ITvTTRODUCTTON. 



Eecognizing that the production of vegetables under glass has been and is 

 rapidly becoming one of the important branches of agriculture, the Ontario De- 

 partment of Agriculture, at the request of the Executive of the Ontario Vegetable 

 Growers' Association, deemed jt advisable to investigate the types of construction 

 of green houses used by American growers. This investigation work covered the 

 principal vegetable growing districts of the Northern and Eastern States, and the 

 following report is intended to convey to the prospective builders some of the details 

 of construction which may help to solve the problem of what is the most economical 

 form of house to build, and otlier points which should be carefully dealt with 

 before the house or houses are begun. The object of this investigation trip was 

 to find the lightest, most durable and most economical type of construction backed 

 by the experience of growers in all parts of the states visited. Over one hundred 

 greenhouse plants Ave re visited and the experience of the several groAvers taken, 

 and all information possible Avas gathered Avhich might be of use in this line. 



The growing of vegetables under glass is yearly becoming one of the very 

 important ends of the A'egetable grower's business. Intensive cultivation of the 

 land out of doors during the summer months has increased the demand for large 

 quantities of fresh produce during this period, and gradually the consumer has 

 begun to Avant fresh vegetables on his table the year round. The building of 

 structures covered with glass and supplied with artificial heat haA^e been intro- 

 duced, and by their use the vegetables are grown to perfection, thus supplying the 

 demand for vegetables each day of the year. 



The greenhouse business in Ontario, of course, has not advanced to the 

 degree that it has in the United States, but Avithin the last five ,years there has 

 been an increase in the building, and there has been considerable improA^ement in 

 the forms of construction. At the present time in Ontario there are seA'eral large 

 plants devoted entirely to the production of vegetables, and a considerable number 

 of the vegetable growers in all districts of the Province haA^e small plants from 

 which they take several crops of lettuce during the season and later use as a 

 starting house for their fielcl crops for the summer. At the present time large 

 quantities of greenhouse-groAvn vegetables are annually imported into Ontario 



