Garlic harvest

does your soil contain any clay? usually such poor water retention would be attributable to not having clay. also the general condition of your plantings is that they are in smaller excavated spaces so that is likely a big part of your wilting. the root systems of larger plants in normal garden soil will be about the same size as the plant mass above the ground... (just an FYI :) )...

anything you can do to block those winds will also help (as long as they do not block all the light).

songbird

Our soil is pretty much decomposed sandstone. It is part of an old ancient lake bed. It is mostly round rocks.

I have found my ground pots work best if I hack them down to over 18" deep and about that much wide too. It is no easy task. Some of those rocks are pretty big.

Smaller ground pots grow smaller plants. Trial and error

Got YUGE peppers growing this year! Well, except for one ground pot that I seriously need to dig out next year. Got one pepper that is about 8" long. Last year's best was about 5" long.

The heat breaks in late August, so I think I will do as you suggest.

It is mineral/rock powder. It does not retain water. I does repel it though. It will eventually sink in, but takes about a half hour of standing. When it dries back out, it is very similar to cement and will throw sparks to a shovel or ax.

organic material and a bit of clay will help keep both water and nutrients in place.

songbird

Peat moss and organic chicken skat based fertilizer plus back fill (2/3 is rock) seem to be doing the trick