344 ON MILDEW. 



moisture similar to that of the atmosphere, 

 the trees will generally be attacked by mil- 

 dew; but when the weather is foggy, and 

 the border be in a tolerable moist state, to 

 the depth and extent to which the fibrous 

 roots run, the trees will rarely be attacked 

 by this disease. This may easily be proved 

 in a Peach house, for let the border be kept 

 dry, and keep the house for a few days in a 

 steam, and the trees will soon mildew. This 

 circumstance I have observed for many years, 

 and have uniformly found it to be the case. 

 Mildew will also be produced from the soil 

 of the border having been planted in for 

 many years, and during that period has not 

 had a renewal of fresh soil mixed with it. 

 In that case a renewal of the border (See 

 the Chapter on renovating fruit tree borders.) is 

 indispensible in order to prevent the disease; 

 therefore it must always be endeavoured in 

 continued foggy weather to keep the border 

 in a proper moist condition. This may be 

 effected by giving it one good watering, so 

 that it will sink to the depth and extent of 

 the fibrous roots. 



When the border in which the trees are 

 planted is of a great inclination, so that 

 rain will run quickly from it, they will ge- 

 nerally be attacked by mildew, and the leaves 

 of the trees will also be frequently curled and 

 blotched. In this case attention must be 

 paid to watering, mulching, &c. 



