Vegetables prefer a full day of sun, but if you live in a shady suburb you don't have to give up the idea of growing vegetables. Here are some minimum sunlight requirements:
*Keep in mind that these are minimums. Increasing the amount of sunlight your vegetables receive will increase the yield and quality of your crop.
*Even though your vegetables may get enough light when planted near a tree, they will not get enough nourishment and water. Vegetables can't compete with an established tree for essential nutrients and moisture.
From GardenGuides.com