Give Roses Full Sun
Roses should receive at least 6 hours, preferably more, of sun each day. Roses planted in shady spots are more susceptible to disease problems because foliage wet from dew or rain will take longer to dry. Also, roses need lots of sun for optimum flowering.
Water New Plants
Coddle new plants for the first growing season by watering as frequently as necessary to keep soil moist but not saturated. Encourage strong root growth by not overfeeding, especially with a high nitrogen fertilizer. Weed the rose bed, then add a thick layer of mulch -- but keep mulch a few inches away from rose stems.
Removing fading flowers from roses -- and many other ornamentals -- will prolong bloom. However, in late summer stop deadheading and allow the roses to produce fruits (or "hips") to stimulate them into entering dormancy.
Spray with Compost Tea
Some gardeners report success controlling foliage diseases by spraying plants with a solution of compost tea, made by mixing one part mature compost that contains some manure with 5 parts water. Let the mixture sit for 2 weeks, then filter and spray at 2-week intervals. The tea also provides nutrients.
Roseslugs are pale green caterpillars that skeletonize rose leaves. If you see dried patches on rose foliage, examine the undersides of the leaves. Roseslugs are the larvae of a sawfly. To control them, hose off foliage in the morning, concentrating on the undersides of the leaves. (Don\'t wet foliage at night, or you\'ll encourage disease problems.) Natural enemies often keep them in check; if infestation is severe, spray the undersides of the leaves with insecticidal soap.