Can I Grow Vegetables In Gallon Cans? 

Q: Can I grow vegetables in gallon cans? 

A: I think you will run into problems with root growth in the small containers.
A 1 gallon paint bucket doesn’t contain enough soil to insure plants’ moisture
needs during the day. If you want to experiment, small plants like lettuce,
radishes and spinach might work. But larger plants, like pepper, squash,
tomato, and okra will dry out quickly during the day. Plastic 5 gallon
construction buckets are a better choice. In one such bucket you could grow
two peppers or a determinate tomato. One bucket could support two okra
plants or possibly one squash plant. Whatever container you choose, be sure to
drill several holes in the bottom so excess water can drain out. Filling the
container with bagged high quality planting soil, not topsoil, is also key.