194 How TO Grow Cut Flowers. 



ing the past three years, both as to cause and remedy. 

 As very few writers agree as to the one producing cause 

 of this trouble, it is reasonable to suppose that several 

 combined may have a direct bearing in the production 

 of this particular form of disease, to which the violet 

 seems to be peculiarly susceptible. Among the various 

 causes assigned are the following: Impaired vitality, 

 springing from the plants being grown in too high a 

 temperature, and propagated while in that condition ; 

 an exhaustion, through long years of cultivation, of 

 properties in the soil essential to their growth; extreme 

 atmospheric changes, and the presence of either water 

 or dew on the foliage during the summer. One large 

 grower plants in frames, where they are to remain 

 summer and winter, carefully' protecting the plants 

 from dew in the fall by means of canvass shutters. 

 Another plants in the same way, but prevents any 

 water from touching the foliage by means of raised 

 and shaded sash placed two feet over them. In this 

 instance water is applied between the rows as is needed, 

 and spider kept at bay by an occasional syringing in 

 the evening with water in which a small quantity of 

 soap has been boiled, the temperature of the water 

 when applied not being less than 100°. The same 

 method is pursued in winter, save that while the 

 plants are in flower the soap is omitted, and the 

 syringing necessary to keep spider at bay is made with 

 clear water of the same temperature, 100°. 



