This tree will require sparse to light watering, full sun because it is needs a warm climate of around 56 degrees. A low nitrogen fertilizer is very useful. When a bloom fades out you have to cut the plant to the point that it is somewhat shorter to prevent rot.
Bougainvillea Bonsai If there is rot it must be cut off completely. Pest control for example caterpillars or green flies use insecticide soap spray which should be applied weekly. This spray is not harmful to humans or animals.
Repot the plant in the spring April or June do not prune the roots severely. Young shoots should be placed in sandy soil with bottom heat applied. A moisture meter is very good when the needle moves it is tine to water the plant. A humidity tray helps to control moisture this is better then spraying the plant it creates a humid environment 24 hours a day.