Water the rose bush at planting. Once you fill the container surrounding the root ball with soil, gently press the soil down and water enough to thoroughly moisten the root ball.
Place your finger into the planting medium daily during the growing season to evaluate the rose bush's moisture level. If the soil feels dry, water the rose until water runs from the container's drainage holes. Watering one or two times daily is not uncommon during dry, hot spells.
Mulch your container-grown rose if you have difficulty maintaining a moist growing medium. Layer about 1 inch of organic mulch around the bush, keeping the mulch from coming into contact with the plant's stem.
Reduce the amount of water given to the rose during the winter, which is when the plant goes dormant and requires less water. Check the soil occasionally and do not allow it to dry out completely. Your rose may need watering only once every month or two during cold weather.