The reason for the legginess is that the succulent projects her growth towards the source of light. As long as your barrel cactus receives the right amount light, whether it is natural sunlight or artificial grow lighting, they will thrive. Let's talk business. When deciding when it is time to repot, consider the following. Healthy, mature desert azaleas will bloom for several more weeks if they are given the right conditions. These conditions are best for plants that have been planted in a pot with sand. It is much easier to care for an underwatered agave than an overwatered plant.