In my last post, “The Beginnings of our Garden,” a reader asked the following: “36 raised beds is a lot of planting space and when you do double that to
72 raised beds that will be a huge resource. I am jealous. But I still
have that question I asked awhile back; how much garden space or raised
beds is enough to grow a year’s supply of food for a family? Would 36
raised beds do it? I do recognize that you plan to have some orchard
trees too and perhaps some grain in the future and of course livestock.
But to restate the question how much garden space would be required to
raise enough food for four people? Not the perfect variety of food or
fodder for live stock but the minimum space that would support a minimum
but adequate diet.“

This is a hard question to answer since literally everyone’s situation is different, but I’ll give it a stab. 

Self-sufficient gardens differ from regular gardens in a number of ways. The main things you need to consider are permanence, preservability, and quantity. In other words, what you plant in your self-sufficient garden should fulfill three primary functions:

1. Plants you like to eat
2. Plants you can preserve them in some non-electric form (i.e. doesn’t require a freezer)
3. Plants you can grow in enough quantity to sustain you

For increased food self-sufficiency, I recommend livestock – chickens, goats, cattle, or other meat, milk, or egg sources.  However if you can’t keep livestock, it’s crucial to grow plant-based protein sources such as nuts and legumes. Hazelnuts, walnuts, peanuts, and dry beans are some examples of plant proteins. If you do keep livestock, these plant proteins will help round out your diet.

Another component to incorporate into a self-sufficient garden is perennial plants. Berries, fruit and nut trees, asparagus, certain herbs, and grapes are all examples of perennials which will regrow year after year with minimal effort on your part.

In a self-sufficient garden, you should concentrate on foods you can preserve through the non-growing seasons.  If you’re overwhelmed with all the lettuce you’ve planted and there’s no way to preserve it for next winter, it’s gone to waste. (Yes, I know you can dehydrate and powder lettuce, but follow me here.) In warmer climates you might be able to keep a garden going most or all of the year, but in northern climates that’s impossible. Instead, we simply concentrate on foods that can be preserved, which captures the garden’s abundance to last throughout the colder months until the garden starts to produce once more. This means mostly canning and dehydrating. Some people also freeze or freeze-dry, though those methods use electricity so we prefer not to depend on them.

Probably one of the biggest problems is when people underestimate how much food they eat in a year. When planning a self-sufficiency garden, the basic rule of thumb is this: Grow more than you think you’ll need. You may be feeding
more than just yourselves at some point.

Offhand I would say a quarter-acre of intensively cultivated garden space would likely go a very long way toward supporting a family of four, especially if it’s supplemented by chickens, fruit trees, etc. But this is nothing more than an educated guess, and it doesn’t include the land needed for grain, fruit and nut trees, and any livestock you have, from chickens to goats to pigs to cows.

The following material is used (with permission) from an article by “Dr. Prepper” on SurvivalBlog.

To help determine how much food to grow, assume the following facts:

•    One pound of beans = ~2000 calories, one 50-foot row produces 5 pounds of dried beans.
•    One pound of corn = ~ 1800 calories, one 50-foot row produces 10 pounds of dried corn.
•    One pound of hard squash = ~ 250 calories, one 50-foot row of produces 175 pounds of squash
•    One pound of potatoes = ~ 450 calories, one 50-foot row produces 75 pounds of potatoes

Divided out equally as your only diet, for an entire year, you would need the following for one person:

•    Beans – 5 fifty-foot rows
•    Corn – 3 fifty-foot rows
•    Squash – 8 fifty-foot rows
•    Potatoes – 3 fifty-foot rows

Assuming one fifty-foot row is 3 feet wide with a 2-foot aisle, that comes to in total in excess of 4,000 square feet of garden (that’s a 63′ by 63′ plot) needed for growing the caloric needs of just one person. Start multiplying accordingly by the number of members in your family or group and you start to see the magnitude of what is needed for a true survival-type garden. It is quite possible that you may need one-half to two-thirds of an acre to feed yourselves. Also, to reiterate, this is based on providing a minimal diet of 2,000 calories per day, which is not a whole lot of reserve for exertion or stress, and this estimate does not allow at all for crop failure or rotation needs, so you really should plan for a larger garden.

What should you grow? There are a few considerations for what to grow in a self-sufficiency garden:

• Grow what your climate will support. No matter how much you might want them, you can’t grow mangoes in Alaska. Become familiar with the USDA Plant Hardiness Zone Map, which most seed companies use when listing their varieties for sale. Local nurseries will usually carry what will grow in your area.  You might also talk to other local gardeners to get their advice.

• Grow what your family likes to eat. You might be able to grow zucchini easily – most people can – but why bother if your whole family hates zucchini?

• Grow what gives you the most caloric and nutritional bang for your buck, particularly if you have a limited growing space. Four crops should be in every self-sufficient garden, particularly if you have no calorie sources from animal proteins: corn, potatoes, beans, and squash. All of these food items are versatile, prolific, and store well under the proper conditions. Varieties are available for almost any gardening conditions, so look into what grows best in your area and with your challenges.  Keep in mind relative amounts of harvest. Out of one raised bed, we can grow 30 lbs. of potatoes, but out of that same bed we might get 8 or 10 ounces of dried beans (which contain more protein).

• Most of what you grow should be preservable in some form, whether canning or freezing or dehydrating or freeze-drying or fermenting or cool storage. Remember, if you’re overwhelmed with all the lettuce you’ve planted and there’s no way to preserve it for next winter, it’s gone to waste.

Naturally all this advice is adaptable for one’s particular circumstances, and considering such factors as skills level, pest pressure, space, water availability, physical strength, time, etc. There are a zillion and one different considerations when answering that initial question “How much garden space do you need?”, but hopefully this gives you something to think about.