One gallon will be very limiting but you can grow some things with a great deal of extra attention to watering and feeding them frequently. A small amount of leaf lettuce, some spinach, 1 Swiss Chard, one head of head lettuce, a 3-5 Nantes carrots, a mini-dwarf tomato plant like Red Robin though it does better with at least 3 gallons, can't think of any peppers, beans, or squash that would work, some herb plants, a few green onions, maybe a few cloves of garlic. That's all I can think off off hand.

Try to rig them up in large trays of some kind that will hold water so they can be somewhat self-watering.

Good luck.

Dave

I grew malabar spinach in a one gallon pot with a bamboo stake. It gave me enough to nibble on when I passed by the plant. You would need several to get much of anything. Maybe 3 radishes per one gallon pot. Some herbs that are small like thyme and parsley might do ok.

Thanks a lot I will try growing some of the leafs and herbs

I've grown quite a few peppers in one gallon pots. You really have to keep up on the watering, though. You won't get a huge harvest of larger ones but smaller pod varieties should do fine. Try Sweet Pickle for a sweet one, nice for salads. Jalapenos, piquin types, cayenne for hot ones. And of course there are lots of ornamentals(many are edible too)that work in smaller pots. I have even grown sweet cheese type pimento peppers in one gallon pots although I only got 2 or 3 fruit per plant. Fun to try in any case, if you're not expecting bumper crops.