How much water is enough?
 

I have a Dr. Huey, and while Im trying to sell my home, I want the damn
thing to keep producing or at the very least keep the leaves it's got.
Unfortunately it doesnt get hit by the auto sprinklers, and I often forget
to water it due to it's size (aproximately 15' high and 5' wide), so I
wonder how much water I need to give it? Is there a measurement chart based
on the rose bushes size?

I use to think that all my roses were getting their watering from ground
water since our ground water is way high, and the roses did great until this
month, now all but about 10 of them are looking rather dull in the leaves
and some leaves are starting to curl, so Im pumping the water back onto them
every other day, but how much?

Thanks,