Thank you both!
gone2seed, I figured it was a sensible thing to do. The fully shaded one seems to be doing the best! I'll put shadecloth on the other two when needed. The one in the ground won't need it when it gets tall enough for the leaves to be shaded by the cloth in the morning, or when the grape fills in it's trellis, whichever comes first, lol.
slowcala, thank you - I'm very familiar with Gardening Australia - they don't have any Brug advice for desert conditions, unfortunately. I'm new to Brugs, not gardening in general, and GA is never very specific, due to time/article size constraints.
To give you an idea how extreme the climate is...
We have tiny gardens... I planted as many trees as possible in front that would take the arid conditions and produce food (like pomegranate), and xeriscaped the rest. I have cacti and succulents galore. At least my yard is alive - you should see some of the others - dead crisped plants. We don't have any humidity to alleviate the effects of intense UV. Over 100f is a normal summer day at the peak.
Many of our native trees don't actually grow in my particular area, naturally. And they need irrigation to stay alive. I used structures where I could for instant shade, but that gets expensive. Our big box hardware places are about three times the prices of yours, sometimes more, and all timber is expensive now. Even DIY is out of the reach of many, unless able to scrounge free stuff.
Three years and some of the street trees are only just starting to get their legs. A lot of them died in the last intense summer. I watered mine, so they're alive at least.
The backyard is the problem child, and where I need to keep these brugs bar the one on the porch - the yard is 8 feet by 59 feet yard, and a few walled garden beds not very big. The largest garden bed - I had a structure made, and 50% shade cloth over that. The rest is concrete.
I have a pink wisteria tree and a few citrus, a snowball viburnum for cut flowers and shading the beds - but everything grows very slowly in our arid conditions, and I can't waste precious (expensive!) water on things that don't give me a return. A lot of space goes to veg. The wisteria was sheer indulgence, but the Brugs captivated me so much I had to try. At least the wisteria gives some shade and will fill in quickly... not an arid area plant, but does well. When the grape fills in it's trellis, it should shade the brug from the worst morning sun. I've spent the last three years trying cultivars of everything that's reported desert hardy.
I spray everything with a kaolin clay product that prevents sun-scorch, and helps reduce transpiration loss - even some of the hardy cacti.
I put in a couple of DIY ollas this year, and that made a big difference to everything, so I'm gonna go into factory mode and make a bunch. But you get an idea how bad it is, when I'm filling a 1 gallon olla every 12 hours plus some top watering. But it's much less watering than I had to do before, so yay!
Thanks again for the advice and well wishes!
to the site Jaya. I am sending you a link to Gardening Australia. You should be able to get some good solid gardening help just by watching these videos. 
