To keep your gardenia healthy and thriving, it's important to water it regularly, especially during hot or dry weather. On average, you should aim to provide your plant with about 1-2 inches of water per week through rainfall or irrigation. You may also want to check the soil around your gardenia plant frequently and water more often if it feels dry or crumbly. Also, keep the soil evenly moist but not overly saturated or soggy. With proper watering and care, your gardenia should be able to bloom beautifully year after year.