This Bougainvillea was purchased as pre-bonsai stock in 1989.
The tree took some years to stabilize under my growing conditions, and for many years never really showed good vigor. In the last few years I have increased its light exposure with metal halide lights and kept the tree a bit drier and potted it in an airy, loose soil mix. This has resulted in much better growth and also in copious flowering lasting months at a time.
The most critical factors for keeping this species happy indoors is avoiding root rot and keeping light levels as high as possible.
Bougainvillea blooms on the ends of new growth so keeping the profile restrained while allowing flowers to develop requires repetitive hard trimming.
Increasing the branch ramification is my goal for the next few years.
The tree is 29 inches tall and 8 inches in diameter.