Plant roses in rich, well-draining soil. When planting, mix organic
matter, such as compost or ground bark, into excavated soil you will
use to backfill the planting hole. Add a 2-3-inch layer of coarse,
organic mulch around roses. Coarse mulch helps reduce foliage
diseases on roses because it reduces the amount of water splashing
onto leaves (splashing water drops can spread fungal diseases).
Irrigate roses deeply but infrequently, applying water directly to
soil using soaker hoses or drip irrigation. Water needs vary based
on weather and soil, so check soil with your finger. Water often
enough to create consistently moist soil – not overly wet, not
bone-dry. To prevent diseases, keep foliage dry, especially if you
must water late in the day.