Hi, Well it really comes down to personal taste. However, in a small garden like yours, you probably want to steer clear of space-hogging crops such as cucumbers, squash, melons, sweet corn, pumpkins and large tomato varieties. Smaller crops such as lettuce, spinach, beans, Swiss chard, radish, and even a pepper and/or small tomato variety or two will fit in there. Again, it's all about what you like to eat and what you can fit in a 4x4 space. To help, you might want to go to the Garden Plans section of our website and look at all the vegetable garden plans we offer there. I'm sure you can find plenty of great planting ideas in that section of our website.