Cute tree and I like the pot too Don. Good to see a post from one of the 'original regulars'. Holiday wishes to you and your family.
Take care,
zube

Very nice but how do you keep it from growing?

This is from an article in my "Favorites".I don`t worry about sealing my cuts.BTW; I have kept mine out on my deck,against the house wall & it has survived several nights of recorded area lows of 28F.It might have been exposed to short periods of about 30F in it`s location.I hope the above article might help on your question--Z

Pruning and wiring: The bougainvillea takes well to pruning; a useful attribute in styling bonsai. Because bougainvillea generally blooms on new growth, each branch, as blooms begin to fade, should be cut back to a point somewhat shorter than the desired length. Seal all cuts to prevent rot. If rot is detected on a collected specimen, cut it out completely.