132 FAMILIAR GARDEN FLOWERS. 
When kept under glass during the summer, the petunia 
soon becomes infested with green-fly, the only mode of 
removing which is to fumigate with tobacco smoke at 
night, when the plants are quite dry, and early the next 
day to give them a slight cleansing shower of clean water 
with the syringe. All plants that are nearly hardy will 
thrive better in frames than in greenhouses from May to 
October, as they can be fully exposed to light, air, and 
dew, and may be protected at any time from storm and 
frost. 
