Value to Space Rating

I’ve been thinking for some time about creating some sort of a database of food plants which will give me an idea of the actual value of growing a particular plant. It’s one of those things that has to be given a lot of thought before I attempt it.

I already have in place an ongoing database of foods with regard to their nutritional status; their calorific values plus mineral and vitamin contents. I started it years ago and really should get going and finish it.

Lo and behold, I find that people are already doing this stuff. It’s called Value to Space Rating (VSR) and here’s a recent post from Suburban Tomato with a link to Mark’s Veg Plot, who is also doing it.

VSR is a means of evaluating how worthwhile a crop is given a certain amount of land.

There are some good ideas in these two posts, so I need to get my act together and do my own evaluation.

Suburban Tomato considers a number of points:

• Cost of food to buy in the shop
• How long the food is in the ground (really refers to annual vegetables and herbs rather than fruit trees)
• How much space is needed to grow the crop
• Value to the garden (attributes other than as human food)
• Taste differential (how does the home-grown version taste compared to the shop version?)
• Hard to find (how available is the food?)
• Freshness (better taste, more vitamins, etc)
• Convenience (good to have when you need it, e.g cut-and-come-again crops)

For the last five on the list she gives a value rating from 1 to 5. The first three involve monetary value, time and area. She has put all this into a spreadsheet. There’s a link to it at her site. A lot of work, but brilliant stuff!

I like her points, but to them I would add nutritional status, something I consider most important.

I make no secret of the fact that I’m not growing my own food primarily because it’s cheaper or healthier or because I simply like gardening, although all these things are true. I’m doing what I do in order to build some resilience into my life in the face of ongoing global energy decline (Google ‘peak oil’ if you don’t know what I’m talking about).

So, being able to survive in an uncertain future is paramount. That means a diversity of food in order to get the best spread of calories, minerals and vitamins, for the best outlay in time, materials and energy (my physical energy, that is, because that’s all there will be when the oil is gone).

Some of the things I will consider:

• Nutritional status (potatoes would get a higher rating than lettuce, for example)
• Time to give a yield (if food is scarce I need to get a quick yield, or starve!)
• Yield (the more I have, the healthier I’ll be and I can barter the surplus for foods I don’t have)
• Ease of growing (e.g soil needs, susceptability to pest & diseases, drought tolerance)
• Ease of storage (especially without fossil fuels—there’ll be no refrigeration)
• Ease of propagation (assuming there won’t be many plant nurseries around, at least in the initial stages of catabolic collapse.

I’ll include all food plants, including culinary herbs, medicinal herbs (especially), vegetables and fruits.

Space isn’t really a problem as I have a couple of acres to play with. Although most of it is remnant bush which is subject to clearing controls and a protective covenant, once the collapse of industrial civilization is in full swing, no-one is going to be worried about what I’m doing here, in fact if things get really bad, I expect I’ll be having to defend my ample source of fuelwood from those who have none (although I’m hoping I’ll be pushing up daisies before it gets that bad!).

I don’t think I’ll put it all on a spreadsheet; a searchable, sortable database will do. I’m not going to be concerned too much about costs and calculations. I already know from from my minuscule food spending that growing my own saves heaps of money.

Any other ideas out there?