I found your information very useful, and one of my favorite trees that you mentioned is the "tapioca" of which I have growing in a very moist part of my garden in the backyard. It is about 4 feet tall and still has all of it's leaves on it. It gets morning sun, but shade most of the day. Is it safe to transplant it right now to where my succulent garden is? I'd also like o know if you would consider the "schizolobium" (brazilian tree fern) as a good shade tree for succulents and cactus.
I live in South Central Texas, Zone 8b, where it gets much too hot and sunny for most succulents to be without shade in the summer. It's perplexing to find a tree that works in our very hot, humid summers, but also will survive our drops into below freezing temps in the winter.
I have a Mexican Oleander and love it. But, alas, it is not terribly winter hardy here, so I grow it as a container plant and put it in a cool greenhouse for the winter. Ditto for my Chinese Floss Tree.
My Desert Willow serves well in one area, although it's not much protection from freezing during the winter as it drops its leaves.
I also use shade cloth in areas and it works great for the summer. It gives little protection for the winter.
So, I guess, I'm still looking for the "perfect" tree for my succulents.
Thanks, Palmbob, for giving us more information and choices.
Schizolobium might be OK in your climate, but in mine it's a spindly tree producing almost no shade whatsoever.. additionally it seems to be a very thirsty tree... mine defoliates if I don't water it frequently during the summer, not something I would want to have to do had it been growing in the middle of a cactus garden. It is one of the better trees in warmer climates for canopy over palms, however. Enterolobiums are also good canopy trees for palms (but again not in my climate).