Water Keep soil evenly moist. That generally means daily watering in hot, dry weather. Stick a finger into the soil. If it feels dry, water. A moisture meter is ideal.
Pinch Encourage branching and bushy habit growth by pinching out stem tips once or twice early in the season.
Deadhead To encourage a steady stream of flowers, remove spent ones regularly.
Feed Container plants need frequent small feedings. Water weekly with a balanced liquid fertilizer diluted to half the recommended strength. Note that some bagged container mixes contain fertilizer. Read the bag, please, to see when you will need to begin feeding.
Prune If plants get leggy and if blooming slows, cut them back hard, then water and feed. They'll bounce back and bloom quickly.