We have a small square foot garden that we have had some luck with this year. We have had a ton of squash which we sliced and froze, a bunch of cherry and pear tomatoes, lots of cucumbers and it looks like we will have a good crop of sweet potatoes in the fall. Regular tomatoes have been few and far between. I thought they would take off like crazy, but they have been slow. The garden is there to supplement couponing and stock-piling. I don't ever see us being self-sustaining - mostly because we can get such good deals on food with couponing and other stuff.
I have NO interest in raising chickens - not when I can get 7 dozen eggs at Costco at a time and we buy chicken breast from Zaycon foods 120 lbs at a time. We bring it all home, process it into bags, freeze and use when needed. For our family, 120 lbs of chicken lasts about 6 months - just long enough for Zaycon to have another event. We also bought 40 lbs of 93/7 ground beef this last time which we processed into browned ground beef with onions, Salisbury steaks, 1 lb packs of frozen raw beef and a bunch of Taco Rice which we froze as well.
We could definitely live off our stockpile for at least 4-6 months only buying milk and small sundry items. We buy milk at Costco and freeze it as well so we could even go without a grocery bill at this point for a month or so. Periodically, we do challenges where we try to "shop out of the freezer" for a month at a time so we don't eat out or grocery shop and transfer the money that was budgeted for groceries into another purchase. This month it was our beach trip. For our family of 5, we budget $600 a month for food, which includes all soap, shampoo, paper towel, toilet paper, shaving supplies, etc. That may seem high to people with smaller families, but it's near impossible to do without couponing/stockpiling.
I love that at any point in time, we can open our freezers and come up with a week's worth of meals at a glance. We may not be rich, but we will not be hungry!