Each season this year I have posted on the Top 5 crops for that season based on their value space ratio. Value Space Ratio is a concept introduced to me by Mark at Mark’s Veg Plot and is a tool I use to try and ensure I am maximising the productive space within my somewhat limited gardening area. The basic idea is to work out the amount of value a crop produces taking into account the amount of space it occupies and how long it occupies that space. The hard part of this calculation is getting the value part right.
For me value is a combination of:
- The monetary value of the crop. I use the Woolworths Online price for conventionally produced produce. This is not because I want to devalue my crops but simply to give a realistic estimate of the base level of how much I save gardening. Also I’m lazy and I can check the prices easily online throughout the year.
- The benefit of having it fresh and readily available. This incorporates both the taste and vitamin benefit you get from eating the crop straight from the plant, as well as the convenience of having the plant on hand and ready to harvest when you need it. An example of a plant which scores really highly in these areas is parsley: you can harvest a bit or a lot depending on your needs. It tastes better fresh and the vitamin content is generally higher when freshly picked.
- The taste differential. While the obvious crop here would probably be tomatoes I also think potatoes score pretty well on this measure. This is entirely subjective of course but also hugely important to me.
- The availability of crop (ideally relatively sustainably/cheaply) elsewhere. Potatoes are not going to score highly on this measure as they store well and are readily available at the farmers markets. Fresh horseradish on the other hand would store well as its not that easy to find. Garlic also scores well here as if you don’t grow your own you are left with a choice of either paying a lot for it at Farmers Markets or buying often tasteless stuff with ridiculously high food miles attached (at various times of the year we import garlic from China, Spain & Mexico).
- The benefit to the garden of growing that crop – this might be aesthetic (I’m thinking chillies or climbing beans here) or as in the case of crops like broad beans, the nutrients they add to the soil.
I don’t think I’ve perfected how to weight each of these categories but using equal weightings across the board these are this years Top 5 crops:
- Silver Beet
If you group the herbs together the list becomes:
- Silver Beet
- Salad Leaves
Based purely on monetary value the list was:
- Silver Beet
- Herbs (lemongrass & coriander scored particularly well)
My tomato crop wasn’t great in 2012 so this affected the scoring a fair bit and in previous years I think they would have made the top 5. Otherwise (the cucumbers excepted) the list is pretty heavily geared towards cut and come again style crops which I guess makes sense as they are generally productive for a larger proportion of the period they occupy space in the garden.