I have one out in the open. I bought it from Home Depot (LaVerne I think). It's in its 2nd spring. Last year I covered it with a shade cloth when temps got over 100. Never seemed happy. Threw out a few stunted fruit and the leaves stayed stubby and dark. This year I'm going to leave out in full sun until I see obvious signs of distress. So far the tree seems happy as a clam. Seems to love the 98-100 degree weather we've been having this week. Many of the leaves have gotten broader, and they are a lighter glossier green, there's lots if purple new growth plus it's been flowering for about a month now. I'll see what happens when temps climb into the 110-120 range. If it suffers greatly, I'll probably move it next February. I thought it was a full sun tree like our other citrus. I didn't know it was an "understory tree".