I cannot get that Citrus tree place in south Texas to respond to emails and that website that says to click to buy from them does not work, so I'm still trying to find a dwarf “Improved Meyer Lemon” Tree to buy that Texas allows to come here. It's possible Lowes in Texas will have them. I think I looked on Lowes on the net and there were none to buy yet.
/johnny
Actually, pea vines might work, as long as you plant them to mature in the spring before the really bad summer heat.