the rose. It causes the leaves to fall prematurely. Spray with bordeaux, 5-5-50, beginning as soon as the first spots appear on the leaves. Two or three applications at intervals of ten days will very largely control the disease. Ammoniacal copper carbonate may be used on roses grown under glass. Apply once a week until disease is under control.
For mildew on greenhouse roses, keep the steam pipes painted with a paste made of equal parts lime and sulfur mixed up with water. The mildew is a surface-feeding fungus and is killed by the fumes of the sulfur. Outdoor roses that become infested with the mildew may be dusted with sulfur, or sprayed with a solution of potassium sulfide, 1 oz. to 3 gal. water. Spray or dust with the sulfur two or three times at intervals of a week or ten days.