The roses in my garden have small orange dots on the back of their leaves. What could it be?

Answer 1

An orange, powdery substance appears on the undersides of the leaves. Eventually, yellow or brown spots appear on upper leaf surfaces. Infected leaves may wilt or curl. Rust, a fungus disease that spreads in moist air and moderate temperatures. The problem is most severe in the Pacific Northwest, where the climate is cool and humid. Remove and destroy all infected leaves, including those on the ground. Avoid overhead watering because the fungus spreads in water. To prevent the disease, spray with a fungicide every 7 to 10 days in cool, wet weather

Answer 2

It is a type of fungus. spray with fungus control for roses