238 



GEEENHOUSE MAKAGEMENT. 



thus providing for ventilation and watering, as a suflB- 

 cient amount of fresh air and rain for this purpose can 

 enter through the openings. In this way, the grapes 

 can be grown with much less care than in tight houses, 

 and good results are often obtained in favorable seasons. 

 On the other hand, if the summer is cold and wet, far 



FIG. 82. BLACK HAMBURG GRAPES. 



better returns will be received if the house is so arranged 

 that the amount of ventilation and water can be regu- 

 lated to suit the conditions. 



In a cold grapery, the ventilation should be grad- 

 ually increased, as the weather warms up, and after the 

 middle of June the ventilators can be left wide open at 

 night until the first of September, except in cold, wet 



