Prune vigorous-growing varieties more heavily than slower growers. Prune climbing roses after their early bloom flush. Remove old, dead and diseased canes leaving about 5 to 6 branches to continue blooming and to produce flowers the next year. When cutting flowers, take a bucket of water with you. Cut them early morning or late afternoon and immediately put them in the water.
Roses have many diseases which are prevented by culture, sanitation and spraying.
Destroy diseased leaves and stems. Keep roses pruned, watered and mulched. Spray regularly to prevent diseases. There are many chemicals to choose from. I would like to see some rose growers try a new one, Immunex , to see how it will work.