As a military Veteran, what healing effects have you found in gardening?

A growing number of Veterans and even current Servicemembers learning to live with the effects of combat trauma are finding their way to gardens. My wife is leading a resiliency garden project on Fort Hood. She has seen some Soldiers beg for “gardening” time. They report its therapeutic effects. Other garden projects are located around the country. Have you gotten into gardening? If so, what specific benefits does it provide you? And how does it help you after you have been to combat?