Croton Picasso Paintbrush should be watered relatively frequently, as the plants like to stay moist. They don't like to sit in water or dry out too much. The easiest way to tell if a plant needs to be watered is by the weight of the container. Croton does best in fertile, well-drained, moist soil. They need bright, indirect light when grown indoors. Outdoors they thrive in partial shade, and in cool climates can tolerate full sun if kept moist (and are acclimated first when moved from inside).