Will this be an all year round outside cactus garden? If my plants are in pots , I move most of them inside during the brief cold spells that we have outside of Austin 8a-8b. Many aloes will do well unground in San Antonio. Many sedums will burn unless in dappled shade here in Texas. I like Sedum palmerii, but I grow others.. It can stay out all year . It is hardy to 0º. Agave bracteosa will do well in shade and dappled sun. dasylerion texana and D. wheeleri will do well in pots. many agaves like A. funkiana, agave blue glow, Agave victoriae-regina can also stay outside. Astrophytum ornatum has been hardy for me in a pot in a semi protected area getting morning sun for me. Opuntia sheerrii will perform well in partshade and is hardy. The list is huge. I like the new ponytail opuntia that is in stores in our area.

I grow mostly Mexican desert cacti, which do well in the Mediterranean climate - hot, dry summers and warm wet winters. They live outdoors all year but go into cold frames for the 3 winter months, to keep them dry. Especially resilient to the hot sun are Ariocarpus - in habitat they are often the only plants that can survive. Other prominent sun bathers are Lophophora williamsii, Encephalocarpus strobiliformis and Astrophytum.

I took a look at your climate and it looks like you get a decent amount of rain, heat, and humidity in early summer. That would lead me to suggest summer growers. Since they will be in containers, if they are sensitive to your winter moisture then you can move them to shelter or use a really fast draining mix.

Here's a breakdown of growing season. http://www.succulents.us/dormancy.html

Thanks so much for the ideas!

I could move them into the shelter of the back porch (deep shade) during freezes. My mother potted up some agave growing wild on their land in the Hill Country and brought them to me. No idea what variety, but they're winter hardy. Meanwhile, my neighbors have some copper sedum growing like gangbusters, but that's the only other one I'm sure of.

The water utility's garden page calls what I have "Dry Tropical Shade", given the heat, wildly varying humidity, and seasonal rain. It really is like a cross between Arizona and Florida.

I grow echeveria runyonii, topsy-turvy and the regular variety unprotected. I grow ghost plant Graptopetalum paraguayense) and 'Blue Pearl unprotected. Desert Savior echeveria AKA Echeveria strictiflora is native to the big bend mountains so likes dappled sun in our heat.This year I was amazed that I have been seeing them being sold at HEB and other nurseries around Austin. I bought several and I am experimenting with them. Some will be potted up come winter time. Others will be left in the ground but they will get covered and one will be left to fend on its own . Most are in the ground. They were $2.98 so I decided to buy several and experiment at that price. I have an unground C&S plot of raised dirt that has been amended with pumice , grit and decomposed pine bark. I grow Echeveria agavoides , Echeveria pulmonoides(SP?), Aloe aristata, Aloe nobiles, Goldtoothed aloe, Aloe striata, Aloe grandidentata, aloe maculata, Aloe dinterii. Aleoe variagata I have in a pot and I bring that close to the house when it gets cold and damp. The combination is the killer.

Our native cactus like lace cactus and horse crippler will do well in pots. They might like your more sunnier spots. Look at the texas cactuses. There are many. Lady fingers cactus (Echinocerious pentalophus) comes to mind. Mine grow unprotected. I think they would like it a little warmer like you are in SA.