Q. Dear Mr. Karwin: I can’t find any guidance in my various gardening books on how much water one should give roses after they have stopped blooming (most of mine have), especially between now the beginning of the rainy season. Any suggestions? Many thanks.
A. Roses should be watered even after blooming to keep them healthy and growing. This is important during hot summer weather, when the plants could be heat-stressed. Be sure to let them dry out between watering sessions, particularly for roses in containers.
Here is independent advice (unfortunately I lost track of the source):
Summer Watering Tips
Roses like infrequent, deep watering as opposed to watering a little bit every day. They prefer a good deep soak and then like to be dried out before receiving another deep watering.
How do you know if your roses need water in the first place? The leaves may droop and lack the suppleness they normally have. (Don’t confuse this with the drooping that often occurs when temperatures exceed 90 degrees).
How will you know if you’ve watered too much? The foliage may feel spongy and may turn yellow. If watering from overhead, do so early enough in the day so the foliage has time to dry out before nightfall. Spraying the leaves with water will often wash away any disease causing spores before they have an opportunity to take hold. So don’t hesitate to do this on a hot, dry day. Your roses will thank you for it!