You do need some "head room" for those babies when they get going/growing! If you read the FAQ and posts you will get lots of ideas for containers. The gallon milk/water jug being the frontrunner - free and easy to get. I would recommend no less then 3-4 inches in the bottom part for soil and at least that for grow room in any container you are evaluating.

Nancy

Milk jugs were my favorite last year. I used 2L bottles for the annuals that sprout quickly, and don't stay in their container very long. Even using the milk jugs, there were several that were growing out the top by the time I got around to planting them out!

I save those mixed lettuce containers and put two bottoms together with a "hinges" of two pieces of duct tape. After poking holes in the top and bottom and planting it, I use one small piece of tape to hold the front together.

I think they make a perfect planter --- too bad we don't eat more lettuce!