264^ THE P HILAD ELPHIA FLORIST. [W* 



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\J)more susceptible of the sudden change of temperature to which we 

 y are subjected, and the weather for two months previous to this is 

 [ generally bright and clenr, the wind prevailing from the south-west, 

 and less sudden changes of temperature. But in July and August we 

 are subjected to violent thunder storms, succeeded by an easterly 

 wind and rain, perhaps for several days, and when such is the case 

 you may expect the mildew to appear, and the vines will require 

 close inspection to detect it, for it is not often discovered till too late. 

 On its first appearance a kind of transparent blotches are observeable 

 on the leaves, of a rather lighter hue than the general colour of the 

 leaf, which may be seen by a careful observer, but by a person taking 

 a cursory glance at the vines it might not be noticed; and if not ar- 

 rested in this stage, it will soon spread over the leaves and shoots as 

 well as the fruit,before you are aware that the vines are at all attacked. 

 I believe giving front air, injudiciously is another cause of mildew. 

 I would only recommend ventilation at the top, and not too much 

 there either, being guided by circumstances ; in fact I am of opinion 

 that vines in a cold house will do well without giving air by opening 

 the sashes, if in glazing the house a small space was left between the 

 laps of the glass, and the vines not trained too near the sashes. This 

 is my theory of the causes, and if the above hints will be the means 

 of bringing out the experience of others more competent than myself 

 my end will be obtained. Some attribute the mildew to excess of 

 moisture, others to want of air, and advocate free ventilation; but I 

 think there is ample proof that want of air is not the cause, for any 

 one may see that vines grown in the open air are always worse mil- 

 dewed than those under glass, which I believe is the only cause why 

 the foreign vine will not succeed in the open air. A vine that is 

 badly attacked with the mildew loses its leaves long before the wood 

 is ripe, consequently the functions of the vine are stopped, and the 

 plant thereby rendered incapable of enduring the frost. It is said 

 prevention is better than cure. The following treatment 1 have 

 adopted in growing vines in pots which will apply to fruiting vines 

 also. 



After starting the vines in the spring at the usual time and in the man- 

 ner which is needless for me to detail, I keep them growing as fast 

 as possible, never suffering them to have a check by a sudden fall in 

 the temperature of the house, keeping up a good heat in the day time 

 and syringing freely, being always careful to watch the change of 

 wind to the east, and put on a little fire, raising the temperature to 

 I admit of giving air for the escape of the evaporation from the flues. 

 1 By this method I have succeeded in keeping the vines free from J 

 CL mildew; as for curing it when once introduced I believe it cannot be Jj 

 (^)done. Sulphur dissolved in slacked lime and applied with a syringe (v 





