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Gardening is often pitched as a relaxing, therapeutic activity—and it is relaxing and therapeutic! But it’s also a sign of how advanced society has become that we can regard growing food as a charming hobby instead of an absolute necessity. On the one hand, that’s a clear sign of mankind’s mastery over the world. On the other, it’s left us remarkably dependent on a system of farming and delivery logistics that has been shown to be distressingly fragile.
Anyone who has ever successfully grown a tomato plant in their backyard has wondered if they could go “off-grid,” grow their own food, and be done with their local supermarket. The answer is yes, but that’s the wrong question. The question isn’t whether it’s possible—the question is how. It’s all about the logistics: How much space do you need to grow enough crops to feed you and your family? Math will help you figure this one out.
Calculate the necessary square footage
If you’ve only ever gardened for fun, or to supplement your store-bought groceries with some tasty home-grown treats, you might not be aware of just how much space is required to feed someone. You may have noticed that family farms are kind of large, and there’s a very good reason for that (though some of that space was traditionally given over to livestock and draft animals). Estimates vary. Different crops require different amounts of space, for example, and some gardening gurus estimate you’d need at least 4,000 square feet per person, with more space allotted for stuff like lanes between crops.
Most of us don’t have 4,000 square feet to dedicate to gardening, but you probably don’t need quite that much as long as you’re efficient. A good rule of thumb is that you need about 200 square feet per person for a self-sustaining garden. So if you’re a family of four, figure you’ll need about 800 square feet, or a space about 20×40 or 10×80.
That’s … still a lot of space, especially if you’re in an urban setting. The key is planning your garden out, because different crops take up different amounts of space, and if you’re going to live off of those crops you have to include a wide variety of plants for nutritional completeness. Your garden will need to include these:
- Proteins. If you’re going to survive on a garden, you won’t be eating meat. While nuts are an excellent source of protein, nut trees take up a lot of space, so make sure you plant beans. Growing lima beans on poles will require about six square feet of garden per person. Snap beans will take about 10 square feet and soybeans will eat up about 30 square feet.
- Carbohydrates. You’ll need some starch in your diet. The good news is that you have a lot of options. Beans will pull double duty here, in fact. Potatoes will require about 25 square feet per person, corn will require about 30 square feet per person, squash will need about six square feet, and peas need about eight square feet.
- Vitamins. A complete diet requires a load of nutrients beyond protein and carbs, so plan on including stuff like spinach (eight square feet per person), broccoli (eight square feet), kale (one square foot), or cabbage (10 square feet).
- Fruits. You can live on vegetables alone, but having some fruits is a great idea. Melons are great (six square feet per person), as are pumpkins (10 square feet), strawberries (10 square feet), and watermelons (six square feet).
- Medicinals & Spices. Some plants don’t offer much nutritional value, but make life a lot better by providing seasoning or health benefits. Some examples include cilantro (one square foot per person), garlic (four square feet), onions (eight square feet), and mustard (two square feet).
If you grow every plant we just discussed for a family of four, you’d need a garden space of approximately 754 square feet of garden—so the 200 square-foot rule tracks pretty well.
Here are the caveats to surviving on your own food
There are a few caveats here, or aspects of a survival garden you really need to think about before you decide that just because your backyard is precisely 200 square feet you’ll be able to pull this off. First of all, the list above isn’t comprehensive and only included a few examples. You might want things like carrots, okra, or cauliflower. This garden size calculator will give you some idea of how much square footage each crop requires. When planning your garden, the main rule is this: Grow stuff you want to eat. Growing food you despise is no way to live.
Other things to consider:
- Variety. Keep in mind that growing just enough food to survive on will wear on you over time. Sure, you could go full Mark Watney and try to live on potatoes alone (and you just might be able to with some supplements thrown in), but if you think entering year two of nothing but potatoes won’t be depressing, you’re kidding yourself. Keep in mind that variety is the spice of life, and diet variety will require more square footage.
- Seeds. Make sure you always select open pollinated seeds so you can recover seeds from your crops and re-plant.
- Spoilage. Growing food is a battle against nature. The moment your crops start to grow, hungry things will show up to eat them in the middle of the night, bugs will nest in them, and diseases will somehow find them. You’re going to need a margin of error if you’re going to live off your garden—and you will likely need a year or two to figure out what not to do and make adjustments to your plan.
- Design. There are many ways to lay out and manage a survival garden. Square foot gardens use raised beds and a grid system to maximize space, keyhole gardens are drought-resistant, and homestead gardens utilize a farm-like layout (and require more space). When planning a survival garden, look at the space you have and consider what kind of garden design will maximize your yield.
A survival garden can bring a lot of relief to your pocketbook and a lot of independence to your life—if you have the necessary space. Hey, no one said going off-grid was easy.