272 PRACTICAL FLORICULTURE. 



possible, spreading the plants so that the air can pass 

 freely among them. 



All Rose growers in winter now find that the best way 

 to prevent the green fly is to strew tobacco stems under 

 the benches or paths, two or three inches thick, renewing 

 them every three or four weeks. Although the odor is 

 hardly perceptible from the tobacco, yet it has the effect 

 of entirely suppressing the Aphis. Of course, this plan 

 would be equally effectual in destroying the insect on all 

 kinds of plants, but is somewhat more expensive than 

 smoking, and the reason of using it in the Rose houses is 

 that the smoks injures the buds. 



Another method, equally effective in destroying the 

 Aphis, is to syringe the plants and then dust them over 

 with tobacco dust. Still another, is to steep the stems 

 until the water gets to be of the color of strong tea, and 

 syringe it on the plants. These last two remedies are 

 really the only ones that can be applied when the 

 Aphis attacks plants out of doors, either method is effec- 

 tive against the black Aphis, which attacks the chrysan- 

 themum as well as against the common green Aphis. 



The Red Spider is rather a more insidious enemy than 

 the Green Fly, and far more tenacious of life, and often 

 does much mischief before its presence has become known. 

 The experienced gardener, of course, should not only be 

 able to detect its presence, but also to discover the at- 

 mosphere favorable to its production. A dry and hot 

 atmosphere, so dry that few plants can long continue in 

 health in it, is such as this pest delights to revel in. Such 

 an atmosphere in hothouse or greenhouse is thus doubly 

 hurtful to plant life, and therefore should never be al- 

 lowed. The remedies are simple; if there is not time for 

 syringing, let water be thrown copiously on the paths, 

 under and on the benches, place pans filled with water on 

 the flue or pipes, or use any other means that may sug- 

 gcet itself, to counteract the aridity of the air, due to 



