This helpful chart is from Uncle Jim's Worm Farm, but your vegetable-planting schedule will vary depending on where in the country you live. The USDA has a handy Hardiness Zone Map, and you can find a more detailed planting schedule here.
A vertical vegetable garden can be the mind blowing solution to your desire to grow your own food in small spaces. Sometimes, you need to look at a problem from a different angle. When it comes to growing vegetables, that means looking up.