One question that arises from time to time concerns the amount of space needed for a garden to be considered productive or self supportive. While I’m not sure what the answer is to that question, I can possibly shed some light on what you can expect a given plot of ground to produce. From there I’ll try and relate this to what it would take for an average adult to live ‘off the land’ as it were.
For starters I’m only going to consider standard row gardens. While you can get great production out of a raised bed garden, you’re still limited to some extent by material costs, custom soil blends, etc. A row garden is something most people can construct with only modest expense. For our example we will take a look at a garden plot that is 104 feet square or a quarter of an acre in size. I’ve attempted to draw a diagram that is to scale and show an average sized ranch style home with a quarter acre plot out back. As you can see, it is a substantial area for a garden.
From information I have gleamed on the internet plus data that I collected from my own efforts last year in my garden (I have raw data if anyone wants it), I’m confident that a harvest of about half a pound of produce per square foot can be realized. (Maybe a little less or a little more depending on the nature of what is planted and on how the season turns out). That would translate out to about seven pounds (7.3 to be exact) of produce from a quarter acre per day assuming that you were able to can, freeze or store all of what you grew and then parceled it out over the course of the year.Note a quarter acre plot would be about 104 feet square.
Now if we accept this
fact and next focus on the caloric content of the produce, we would find that some vegetables are low, some medium and some high in the number of calories you get from them on a per pound basis. At the high end would be potatoes that can approach a calorie per gram or 453 calories per pound. At the low end, say lettuce for example, you are getting hardly any calories. Maybe ten to twenty per pound grown.
So, if you happen to be an average sized adult and your daily caloric requirement is 1800 calories per day, that would translate out to a yearly need of (1800 cal x 7 days per week x 52 weeks per year) or about 374,400 calories that you would need to eat each year. Now, assuming an average of 7.3 pounds is produced per day in a quarter acre plot at an overall average of 200 calories per pound, you would get (7.3 x 200 x 356) or 512, 640 calories. That’s more than enough to live on even assuming some spoilage and loss to critters.
