Plastic out here, regardless of the type or what you want to call it, all has the same effect. Nothing grows under it. When it's 118 in the Sun, and the ground temperature is so hot you'll burn your feet if you leave them on gravel for any length of time, it's going to kill the germination of anything. Much like planting something in a frying pan on your kitchen stove.
Even concrete gets far too hot to walk on with bare feet. When I let my dog out during the afternoon on these kind of days, he won't walk on it. He'll just walk along the pool on the Cool Decking, then trot under a tree to do his business. This type of heat can be dangerous. A closed up car in afternoon Sun can see inside temperatures go over 150 F. Every year dogs, and sometimes kids die from idiots who leave them in cars while they run errands.
People are encouraged if they see such nonsense, to break the windows of vehicles to relieve who or whatever living is inside. Cops will do it automatically, then be waiting with handcuffs when they come out. You would think common sense would prevent people from doing this to kids and pets, but it happens all the time.