One of the problems with container gardening in my area is that you generally have to water the plants every single day in the summer (except on occasion) or else they have a high likelihood of dying from lack of water (even if you only miss one day). This is not because the plants drink lots of water. It's because the water evaporates fast. (Edit: I know because the containers dry out whether or not there are any plants in them, and I've never had mature plants in them, since they tend to suffer in those fast-drying conditions; the climate is hot and arid in summer, with lots of sun.) I imagine the containers have been between 2-8 gallons.
Anyway, I know about self-watering containers, but I'm looking for other easier and less expensive alternatives.
One idea I have is to cover the top of the containers with plastic and just have a small opening to plant the plant. That should in theory hold much more water inside. Do you think this will work? Why or why not? Have you or has anyone else tried it? Assuming there are no weed seeds, do you think clear plastic would be better than black plastic?