194 MASSACHUSETTS HORTICULTURAL SOCIETY. 



time, but this cau generally be prevented by wetting down the 

 paths ; in doing this, however, care must be taken not to wet 

 the plants ; they must never be wet when the sun is shining hot 

 upon them. In watering these plants, it does not matter whether 

 it be done in the morning or the afternoon, provided the water is 

 quickly dried off the plants. When a new bed for a crop of let- 

 tuce has been prepared in a house, it should be thoroughly wet 

 down three or four hours before planting, but the soil should not 

 be muddy when the plants are set. After the planting is com- 

 pleted give a light watering. Where a bed is built two or three 

 feet high, with an air space beneath, it requires more watering. 



In preparing a hotbed to start a lettuce crop in December, 

 there should be a foot and a half of hot dung put in for the neces- 

 sary heat. In January the circumstances are very different, and 

 one foot of dung would suffice. The amount and frequency of 

 watering would depend largely upon the weather. 



Samuel Hartwell spoke of a greenhouse, five hundred feet 

 long, devoted to forcing vegetables, which has been run four 

 years without a change of soil. Some of the plants in the last crop 

 were blasted. 



Mr. Philbrick said that a new greenhouse could sometimes be run 

 three or four years — somethnes only one year — without trouble 

 from fungus, where the same soil is used continuously ; but, as a 

 rule, in all such houses crops will sooner or later begin to fail. If 

 fungous diseases do not appear, insect pests are almost sure to do 

 so. Generally it is necessary to take out the old soil to the depth 

 of about six inches and replace it with fresh earth, when rotation 

 of crops cannot be practised. 



Mr. Hartwell asked what insects most generally infested such 

 greenhouses. 



Mr. Philbrick replied that the most generally troublesome 

 insects are the aphis, the red spider, and the cut-worm. Fumiga- 

 tion with tobacco will usually prove a remedy for the aphis. For 

 the red spider, wet down the plants as often as it can be done 

 safely. The cut- worm is active at night, and by going around 

 frequently in the evening, the gardener can find them at work and 

 crush them. 



John Parker suggested the use of a ring of stout manilla paper, 

 or of wood, made large enough to pass over the plant and rest on 

 the ground. No cut-worm will ci'oss it to the plant. 



