One of the main problems with container gardening in a desert environment is the overheating of the plants' roots. In contrast to a normal plant with its roots insulated deep in the ground, the container plant's root system is separated from 100 degree (37.8 c) plus temperatures only by a small amount of dirt and the thin walls of its container. Further, as the hot desert Sun shines on the container walls, the soil temperatures inside climb even higher. These conditions often combine to bake a plant's roots and impede its development.
The other day, as I was putting my reflective windshield screen up in my car, I had an idea. If the reflective material is so effective at keeping the Sun out and temperature down inside the closed environment of my car's interior, the same should be true about the temperature inside a plant container. So, with this in mind, I grabbed some aluminum foil and went out and wrapped it around the 15 gallon (56.7 liter) container into which I had recently transplanted a Black Prince tomato seedling.
The foil experiment seems to have been successful. During the hottest part of the day, the soil temperature in the wrapped container is noticeably cooler than in the unwrapped ones nearby. The only downside is that it looks like something that should be on a spaceship.
The panel for our solar powered walkway lights adds to the spaceship look.