X ROSES UNDER GLASS 173 



In a cool house like this nothing but protection is 

 aimed at, but that is quite sufficient to make the plants 

 bloom much earlier than they would in the open 

 air. They should not be pruned before January, if 

 there are no means of keeping the frost out in 

 severe weather, and in the meanwhile the soil should 

 be cultivated and cared for in the usual manner. As 

 soon as the plants commence growing, however, they 

 will require a good deal of attention, and some at least 

 of the many troubles of growing Roses under glass will 

 be experienced. 



Every outdoor pest has also to be contended against 

 under glass, and mildew, red spider, aphides, and thrips 

 are even more troublesome than in the open. One of 

 the greatest difficulties is the maintaining just the 

 right amount of moisture in the air. If there be too 

 much, mildew will probably show itself, and may soon 

 make terrible havoc, the tender leaves being much less 

 able to resist it than the hard foliage of outdoor Roses 

 at Midsummer. Incautious ventilation, to dry the air, 

 will probably increase the evil, unless the weather 

 outside be very mild. If, on the other hand, there be 

 a lack of due moisture, red spider and thrips are sure 

 to appear, and may do as much damage as the mildew. 

 To hold the scales evenly in this matter of moisture 

 is one of the most important points of successful cul- 

 ture under glass, and it seems difficult to frame any 

 special rules on the subject save those that are founded 

 on experience with a knowledge of the dangers on either 

 hand. The uninitiated would probably err in keeping 

 the plants in pots too dry ; syringing them three times 

 a day seems a strong measure and likely to lead to the 

 danger of mildew, but it is practised by some of the best 

 growers during April and May ; we are apt to foi-get, 



