Question
how do you prevent disease and keep the roses healthy?

Answer
Carmen, the best defense for a Rose is to keep it healthy and spray it for fungus and blackspot BEFORE symptoms appear in the spring.

Healthy Roses need full sun and lots of water.  They need to be fed and they need to be sprayed when necessary.  Japanese Beetle larvae overwinter in your lawn; if you get them before they become adults, you won't have a Japanese Beetle problem with your Roses later.

Companion plants help keep Roses healthy, too.  Without chemicals.

What kind of diseases are you concerned about?  Anything specific?  rsvp!