376 MINNESOTA STATE HORTICULTUEAL SOCIETY. 



Roses on their own roots are usually preferred, for if they live there 

 will be no doubt as to their quality. They are produced by taking 

 cuttings from the new growth and rooting them in sand. It is 

 necessary to do this in a greenhouse. 



9th. Diseases and Insects. — As in everything else the old saying 

 "An ounce of prevention is worth a pound of cure," holds good in 

 this case. The best way to prevent disease in rose bushes is to give 

 them good cultivation and do all that is necessary to secure a strong, 

 vigorous growth. Disease always attacks the weak more quickly 

 than the strong; and this fact must be carefully borne in mind, 

 thorough cultivation is absolutely necessary in combating the 

 ravages caused by disease and insects. 



Sudden changes of temperature may cause mildew, and it can- 

 not be prevented as it can in the greenhouse. Dusting the bushes 

 with sulphur will assist in preventing it. Keep up the cultivation, 

 furnish moisture, and as the weather grows warm again the plants 

 will revive and outgrow the disease. 



The Red Spider — Is most likely to attack the bushes when it 

 is dry and warm. They are very small and are not discovered until 

 they have become numerous. The bushes begin to look unhealthy, 

 and the leaves have a sickly appearance and will begin to drop off 

 unless the insects are killed before they have reached the last stages 

 of disease. They can be controlled by spraying with cold water and 

 keeping the bushes quite damp. Morning is the best time in which 

 to do it, and the under part of the leaves require special attention. 



The Aphis — Can be controlled by spraying with tobacco water. 



The Rose-Thrip. — A very small white fly or midge that is found 

 on the under side of the leaves ; can be destroyed by spraying with 

 tobacco water. This also acts as a preventive of this pest. 



The Rose Bug — Is a beetle which attacks the buds before they 

 have had time to develop, and eats out the center. A poison to de- 

 stroy these would need to be so strong that it would necessarily in- 

 jure the plant; so the only alternative is to pick them off and destroy 

 them as potato bugs are destroyed. Fortunately but few localities 

 are troubled with this pest and persistent effort will abate the nuis- 

 ance. 



The Rose Slug — Is the most troublesome of all the pests that 

 molest our outdoor roses, but a knowledge of the habits of its pro- 

 genitor will enable the grower to eradicate it quickly. It is the larva 

 of the saw-fly. This fly comes from the ground during the latter 

 part of May when the rose foliage is reaching good form. The fe- 

 male deposits its eggs in incisions made in the leaves on the under 

 side. These eggs hatch in from 12 to 15 days, and the little grub 



