Well my knowledge and experience with this tree is limited. Here's my take on it. It grows at elevation in northern Mexico, so is apparently modestly frost tolerant and drought tolerant. I've seen an image of a 25 to 30 tree, so 15 feet max is inaccurate. I have one I got from Yuccado in Texas about four years ago. It's now a narrow seven foot sapling. It's been evergreen for me in SoCal. Seems to be quite drought tolerant. I don't water it all in Winter but I suspect if I had watered it more in Summer, it would be bigger by now. I think in your Texas climate it will grow faster with a fair amount of water in summer. The foliage is very very pretty. Mine hasn't bloomed yet but I saw pics of blooms on a three foot plant.

Hope this helps.

-Ron-

Thanks, Ron.
I had a reply on the Texas Gardening forum that theirs froze at 20F in an open location; but others that were understory planted survived. They were in Austin, Tx. So, I should be very safe in Houston. I am going to put mine in full sun to aid in blooming, and watering is not a problem. Also, I like Yuccado - I visited them several years ago, and wrote a brief article on them for my MBA program. They cooperated fully with detailed information.
Nick