Roses appreciate lots of water. Water generously, at least 1 inch/week, preferably 2 inches/week during growing season. Water every 4‑7 days during the summer when needed. Each bush needs about 4‑5 gallons/week during the hot summer.
Roses get all their food either through their leaves (foliar feeding) or through their roots. The only medium for transporting food is water.
Infrequent deep watering is preferred to frequent light watering to help promote a deep root system. Deep root systems help the rose to survive both droughts, and winter freezes. Frequent, light watering causes roots to form very near the soil surface, making the plant more susceptible to summer ‘baking’ and winter freezes.
Try to avoid getting the leaves wet (which promotes disease) when watering late in the day. However, on hot days wetting the foliage can reduce transpiration and relieves heat stress.