A friend gave me a Boganvillia Plant. I knew
nothing about them, so I repotted it, fertilized
it and set it out where it got a little morning
sunlight. It did marvelous and is now very big.
It had some beautiful blooms on it early in the
summer. I live in Texas and would like to save
the plant through the winter to put back out
next spring ----so, what do I do with it. Maggie

You did everything right so far - good job.
For my article on growing bougainvilleas
click here
The last two paragraphs explain how to keep it through winter.