Full sun, well drained soil is preferred. I'd water the hole you plant it in and then rewater to settle the soil once planted. After that, water once a week "about an inch" or if it's really hot water twice a week. A bulb type fertilizer or tomato fertilizer as Triple said should serve you well. Mulch around the roots with compost or something to help keep the shallow roots moist and retain moisture.
Keep deadheading old blooms and more will appear! Good luck.