I water twice a week all year long and for spring, summer and autumn I keep them in a saucer of water.
They are one of my favourites with their strong fragrance and their ability to bloom several times a year.
I've got mine on the north west facing kitchen window sill and they seem to like it. Do you keep the saucer of water topped up or just to catch any run off?
I wish that I had more windows sills!