All vegetables, with the exception of mushrooms, need some sun or another light source to grow. Plants convert sunlight through photosynthesis to a food source they use for energy. Without the light there is no photosynthesis which means no food, no growth and the plant dies. Some plants can grow in shady places without direct sunlight and others thrive in all day sun. Before planting any vegetables, determine how much light it needs to thrive.
Most leafy greens like spinach, mustard greens, kale and chard, will grow in the shade, just more slowly than in sunlight. Lettuces such as red oak, romaine, iceberg and leaf lettuces will grow in shade as well. Root vegetables will grow leafy tops in the shade but the root formation, the edible part of the plant, will grow slowly. Root vegetables may get woody before they're big enough to harvest. Rhubarb is the only vegetable that will grow in deep shade, according to Charlie Ryrie, author of "The Country Garden." Rhubarb has deep red stems and bright green large oval-shaped leaves. The stems are edible and the leaves are poisonous.
Cool Season Vegetables
Any vegetable that produces flowers and then sets fruits requires sunlight. The plant may grow green leaves but it won't flower without the sun. Peas are an example. Edible flowers such as broccoli and cauliflower won't set heads without sunlight. The part that is eaten is actually immature flower buds. The head of the cauliflower exposed to sunlight turns green. The flavor isn't affected. Most gardeners tie the leaves up and over the head to keep the cauliflower white. Other cool season vegetables that require direct sun are cabbages, celery and Brussels sprouts. Celery stems turn greener the longer the plant grows. Warm weather causes most cool season veggies to bolt. That is the plant stops growing and starts to throw up a flower stalk. The taste of the veggie deteriorates when it starts to flower.
Warm Season Vegetables
Warm season vegetables require sun to grow and produce a crop. Most are actually fruits where the plant flowers and produces seeds that are encased in an edible outer shell. These plants require warm temperatures and long days to mature. Warm season vegetables include cucumbers, tomatoes, eggplant, bush beans, lima beans, pole beans, corn, squash, green peppers and hot peppers. Plant these veggies where they receive all day sun. In very hot areas, such as the southwest desert areas, provide afternoon shade.