In the preface to my book, Gardening: An Ecological Approach, I offer five reasons to grow a garden. Of course, there are as many reasons as there are gardeners. My list is biased by my interest not only in human health, but also in ecology, global environmental issues, and wildlife/wilderness conservation.
Here's reason #1:
To Grow Food For Health
"People in developed nations (like the U. S.), where food is grown, processed, and distributed industrially, are subjected to a counterfeit form of nutrition where mass production efficiency and corporate profitability are most likely the driving forces in food production. That people acquiesce to this situation is evidence of the persuasive power of advertising, the 'busy-ness' of people's lives, and the general failure of education at all levels to make people aware of the incontrovertible link between food, diet, nutrition, and health" (p. xi).
A personal garden, or a personal plot in a community garden, is one of the most economical, reliable, and satisfying ways to provide oneself with safe, nutritious, organic food.
Learn more in Gardening: An Ecological Approach.