What if I want a tiny farm?

May 14, 2009 8:37 PM

How big is the smallest possible subsistence farm?

Settle a living room bet -- what's the smallest amount of land on which a vegetable farm could feed a family of two for more than a year or two, barring famine or harsh winter or whatever? Let's say an Upstate New York-esque level of soil quality. How would I even go about solving this question?

posted by zvs to food & drink (22 comments total)

Clarification: is it okay to take this land and build, like, multi-story warehouses full of hydroponics on it?
posted by box at 8:46 PM on May 14

Potatoes produce more calories per acre than just about anything else, at about 9.2 million per acre. Using the usual 2000 calories/day gives us 1.46 million calories per year for the family of two. A little more math and we get .159 acres of potatoes being sufficient.

That's just bare calories, though, and doesn't take into account that subsistence farmers probably need more than 2000 calories/day. It also doesn't take into account the fact that you need seasonal harvests. Potatoes and other cellar vegetables keep for a long time, but I would bet my survival on it.
posted by jedicus at 8:59 PM on May 14

Argh. wouldn't bet my survival on it.
posted by jedicus at 8:59 PM on May 14

No warehouses!
posted by zvs at 9:01 PM on May 14

Purely vegetable? Chickens and pigs generate a lot of useful protein from your inedible waste.
posted by i_am_joe's_spleen at 9:01 PM on May 14

This one's pretty darn small.
posted by leotrotsky at 9:03 PM on May 14 [1 favorite has favorites]

Here's a nice photo of their layout. They not only support a family of 4 on a regular size lot, they produce excess produce, eggs, and dairy to sell to local restaurants. And they make their own biodiesel.
posted by leotrotsky at 9:06 PM on May 14

Square Foot Gardening says that 3 4'x4' plots will provide a summer season's-worth of vegetables for one person.

So double that to provide veggies through the winter (assuming you can't have perfect overlap and still get a good late-fall crop, and assuming good canning skillz and all that), double it again to provide for two people, and you're looking at about 200 square feet. Well, according to the guy who invented the technique, so YMMV, I guess.
posted by bcwinters at 9:06 PM on May 14

1000 square feet per person. Based on the techniques taught here by this guy.
posted by Lexica at 9:11 PM on May 14

The three sisters (corn, beans, and squash) are fairly nutritionally complete. Parsnips are calorie dense, store well, and have a harvest season that complements corn, beans, squash, and potatoes.

Assuming a calorie density equivalent to corn (7.5 million per acre), the three sisters would require about .2 acres to feed your family of two. I think splitting the farm between the sisters, potatoes, parsnips, and greens (lettuce, spinach, kale, etc) would give you a broad harvest season, reasonable nutritional completeness, and lots of storage vegetables. Call it a third of an acre to allow for some loss.

Of course, the quoted figures are for modern farming methods. I imagine you'd have to allow for a lot of margin if you're talking about amateurs.

200 square feet
1000 square feet per person

No way. The densest crop (potatoes) requires 3267 square feet per person just to give subsistence calories, much less complete nutrition, and that's with conventional farming methods.

The urban homestead that leotrotsky linked to looks about right. Of course, dairy and eggs are much more calorie dense than most vegetables, and the (I assume) goats and chickens can be fed vegetable scraps. It's outside the scope of the question, though. A pure vegetable garden is going to need more space.
posted by jedicus at 9:20 PM on May 14 [1 favorite has favorites]

These people do it on a regular Pasadena house block. I've seen it with my own eyes and it's incredibe.
posted by lottie at 9:36 PM on May 14

These people do it on a regular Pasadena house block.

What they're doing is very impressive, but they aren't self-sufficient. From their site, the percentage of self-grown food they consume:
Winter 55% Spring 65% Summer 80-90% Fall 65%

They do that on .1 acres of garden and use eggs and dairy (they also grow fruit, which also appears to be outside of the literal scope of the question). They're also in Pasadena, which has a pretty fantastic growing climate. Given all that, I stand by my estimate of a third of an acre for two people in Upstate New York.
posted by jedicus at 9:43 PM on May 14

Minor correction: the Path to Freedom folks (while super awesome!) don't, I don't think, do dairy yet, and while they do support themselves in fresh and canned veggies and fruits, they also eat a lot of rice and pasta from grains they don't grow themselves. They post weekly meal wrap-ups almost every week, which I find useful and inspirational (though I get jealous at how much earlier their season is).

Modern first-worlders would probably need to do a lot of diet modification to be a true subsistence farmer on a small lot. Dried beans and grains would be a luxury. At my house we grow as much of our own food as possible, and we ate a hell of a lot of potatoes this winter. We certainly weren't anywhere near entirely self-sufficient on our 1/3 acre though we could have tried a lot harder. Getting another half-acre, plus, under cultivation this year.

And on the topic of potatoes, I have this random factoid rattling around in my head about how potatoes plus dairy is nutritionally complete? Not sure if it's true, and I can't find a good source now, but it may have been mentioned in Michael Pollan's The Botany of Desire.
But to get dairy you have to breed your goat or sheep or cow, and she has to eat, and so you need grains and turnips and other crops for her and her baby ... Hence Dexter cattle!
posted by librarina at 9:56 PM on May 14

For those interested in looking deeper into this question, the John Seymour book "The Self Sufficient Life & How To Live It" is unbelievably awesome.

It's a practical, illustrated, detailed guide to exactly what has to happen on a piece of land to make it work.
posted by Aquaman at 10:39 PM on May 14 [2 favorites has favorites]

I think you want to start with the above mentioned John Jeavons and his book How To Grow More Food Than You Ever Thought Possible On Less Land Than You Ever Imagined.
posted by sully75 at 2:19 AM on May 15

The family plots of the three sisters mentioned above in the mayan ejido's I visited in Mexico years ago were roughly about a half acre. This did not count the sustenance received from the pigs and chickens that ran wild in the village or the wild game, fruit, and roots gathered in the jungles around the village. Because of the climate they might actually get two harvests each year of beans and squash (not corn).

With modern fertilizers and gmo crops you could get a heck of a lot more out of a half acre than those dirt poor Mexicans were subsisting on.
posted by Pollomacho at 4:47 AM on May 15

Based on experience (I have a BS in Horticulture and am about to finish a MS in Crop Science) I would say 1/2 to 3/4 acre could feed a 2-person family all year long, but you'd have to dedicate your life to it (literally). It would take some very intensive farming, use of row covers, high tunnels, vermicompost, smart cover crop rotations and nutrient management, etc. You would also need to learn to preserve and can much of your food from the summertime so that you'd have a good variety the rest of the year. A root cellar would also be mandatory. There would also be many foods that you eat today that would be impossible to grow in upstate NY, and some that you wouldn't grow even if you could (e.g. maybe they take too much space, time, etc). And so forth...
posted by bengarland at 6:35 AM on May 15 [1 favorite has favorites]

I think this pretty much proves you can do it on an ordinary home lot.
posted by ecorrocio at 7:44 AM on May 15

My mother grew up on a sustenance farm. They had a horse plow, a cow for milk, and a few chickens/pigs. I think they bought sugar for baking, but milled their own flour, made their own butter, pressed their own cider, pickles, preserves, and so on. They fed up to 11 people (two adults + nine children) on 1 3/4 acres with food to spare. It's not the acreage that's the limiting factor, it's time.
posted by mrmojoflying at 8:26 AM on May 15

Terrific! Thanks all for helping me be a home ec nerd. Can't start a garden without some serious statistical background...
posted by zvs at 12:44 PM on May 15

So double that to provide veggies through the winter (assuming you can't have perfect overlap and still get a good late-fall crop, and assuming good canning skillz and all that), double it again to provide for two people, and you're looking at about 200 square feet.

That is not nearly enough.
I met a Berkeley grad student who did the following experiment: could he grow enough vegetables to feed himself and maintain soil fertility without outside inputs (buying fertilzer)? He did this in Santa Cruz, California, for seven months. He only ever bought salt and nutritional yeast. He told me that yes, he could live, but he was: constantly hungry, frequently working on his plot (4-6 days per week, full time), and when not working, either eating or sleeping. He apparently lost a lot of weight.

"Altogether, 125 square feet of bed space produced 1.6 cups of steamed vegetables a day from April 10 to October 26. "

He had 2,500 square feet of garden in the French Intensive Gardening style, plus an additional 2,000 feet for composting, propagation of seeds and cuttings, and paths to work the garden (wheelbarrow width). So, 4,500 square feet for a young guy in Santa Cruz. Even if for some insane reason you weren't composting all your garden waste and relied only on fertilizer bought at the store, you'd probably not want to be on a starvation diet through a New York winter. You'd need space for chickens and rabbits, and you would have to grow food for them as well (you'd feed them with the stuff you would normally compost, plus some grain to fatten them up). So you'd grow and store more food than he did. I wouldn't expect to live as a subsistence farmer feeding a family of two on less than 9,000 square feet. The Dervaes family in Pasadena don't feed themselves entirely from the food they grow, and they live in a climate where things grow fast all year round. Even chickens lay more eggs in warm climates.

Here's more info on his project. You can see in the chart that other than potatoes, he actually yielded more than the US average (in some cases, significantly more) for the crops he grew.

That square foot gardening calculation that is linked above is the calculation to provide supplemental vegetables, not an entire three square meals.
posted by oneirodynia at 6:24 PM on May 17

The 1000 sq ft per person quoted above is apparently pretty accurate, assuming you're in a climate that supports it. If you're somewhere less arable, scale appropriately.
posted by talldean at 5:56 AM on May 22