32 CULTURE OF THE ROSE. 



A good soil, a good situation, free air and full sun, 

 joined with good manuring, good pruning, and good 

 subsequent culture, will prevent more diseases than the 

 most skilful practitioner would ever be able to cure. There 

 are certain diseases, however, to which roses, under the 

 best circumstances, are more or less liable. Of these, the 

 most common, and perhaps the worst, is mildew. It con- 

 sists in the formation on the leaves and stems of a sort 

 of minute fungus, sometimes presenting the appearance of 

 a white frost. Though often thought to be the result of 

 dampness, it frequently appears in the dryest weather. 

 Many of the Bourbon roses, and those of the Hybrid Per- 

 petuals nearest akin to the Bourbons, are peculiarly liable 

 to it. In the greenhouse, the best remedy is sulphur, 

 melted and evaporated at a heat not high enough to cause 

 it to. burn. In the open air, the flour of sulphur may be 

 sifted over the diseased plants. English florists use a 

 remedy against mildew and other kinds of fungus, which 

 is highly recommended, but of which I cannot speak from 

 trial. It consists in syringing the plants affected with a 

 solution of two ounces of blue vitriol dissolved in a largo 

 stable bucket of water. 



