ROSES UNDER GLASS 139 



water, and at the same time the plants should not be 

 allowed to become dry at the roots. In addition to this 

 the hot-water pipes should be smeared with sulphur 

 made into a paste by the addition of a little milk. 



Mildew. — This is the most troublesome enemy of 

 all to deal with in a Rose house if once allowed to 

 establish itself, but if dealt with very promptly it can 

 readily be kept in check. It most frequently arises 

 from injudicious ventilation causing cold draughts 

 of air to descend upon the tender foliage, for although 

 Roses like a buoyant atmosphere they soon suffer 

 if exposed to a cold current of air, and more parti- 

 cularly if the house has previously been kept too hot 

 or too close. The two great safeguards against mildew 

 are judicious ventilation, and coating the water pipes 

 with sulphur as recommended for red spider as soon 

 as the plants come into leaf. This coating should 

 be renewed about once a fortnight, for nothing will 

 prevent the spores of mildew from finding congenial 

 resting-places more effectually than the fumes of 

 sulphur. However, notwithstanding all these pre- 

 cautions, should the slightest trace of mildew be seen, 

 the plants affected, as well as the plants near them, 

 should be at once dusted over with flowers of sulphur. 



Rose Grubs. — In the early stages of growth these 

 should be sought for and destroyed as soon as detected, 

 hand picking being the only effectual remedy. But 

 these pests will not be found nearly as numerous as 

 in the case of Roses grown in the open air. 



The Summer Treatment of Pot Plants. — When the 

 plants have flowered more air should gradually be 



