138 ROSES FOR ENGLISH GARDENS 



be necessary, when the outer atmosphere is mostly so 

 humid, but few people are aware how dry the air in a 

 greenhouse can become under such conditions, and 

 more particularly when there is considerable difference 

 between the inside and outside temperatures. When 

 the plants are in bloom the house should be shaded 

 during the sunniest part of the day, and air admitted 

 to reduce the temperature inside the house. By this 

 means the flowering period will be extended, and the 

 individual flowers will be finer than would otherwise 

 be the case. 



Insect and other Pests. — As with such pests in the 

 open ground, so with those in the house, prompt 

 measures are the only safeguard. The three great 

 enemies of the Rose under glass are aphides or green- 

 fly, red spider, and mildew. 



Aphides can be readily kept under by fumigation, 

 which should be carried out the evening after the first 

 greenfly is met with, and the dose repeated on the 

 following night. A careful watch should be kept for 

 the reappearance of this pest, and the same plan 

 followed as before. If these directions be only faith- 

 fully carried out, greenfly will give little trouble. 

 Richards' X.L. All vaporizing Liquid, or other similar 

 preparation of nicotine, used according to the instruc- 

 tions supplied with it, will be found simple, cleanly, 

 and effectual. 



Red Spider. — This usually appears in spring when 

 the air in the house has been allowed to become too 

 dry. In order to destroy this pest the under side of 

 the foliage should be frequently syringed with clear 



