@pod Kristi, I'm not sure where they begin. I'm not sure why they don't grow here. Too cold or dry heat pr a combination of those maybe. Post Oaks are the primary native trees here, but lots of mesquite and some pecan trees. By the time you drive over to Abilene which is prox 50 miles west, the oak trees have given way to mainly mesquite. Post Oaks aren't inclined to play host to other things. I've never seen mistletoe in one. It will occasionally get in a Blackjack Oak, but not the Post Oaks. I have a couple of mots of Live Oaks which Tillandsia likes a lot, but they aren't growing on the trees here. Tillandsia sure grows on the Live Oaks and Juniper in the hill country.