In this chapter I will use the data we've gathered over the last 5 years to provide a rough guide to how much space you need to be self-sufficient. Although we don't keep records of each individual crop that we've harvested, we do know that we've been self-sufficient for over 3 years, we've harvested over £37,000 worth of food and we've harvested over 30 cubic metres of fruit and veg. That's reasonable sample size to draw some conclusions from.

It's difficult to be definitive though because everyone eats a different mix of fruit and veg, different quantities per meal and a different numbers of meals a day. To make it worse, if you eat a lot of preserves they consume a huge amount of fruit, to make a very small amount of jam, sauce and ketchup, by comparison to eating fresh. Despite these challenges, it's worth making an attempt at an answer.

The start point is my estimate of how much we harvest. I have this information in two forms.

  1. Harvest value
  2. Number of meals

By taking this data we can provide two ways to think about how much space you will need, by estimating how many fresh meals you eat a day, or by estimating how much you spend on seasonal fruit and veg.

First though lets take a deep dive into my data!

Calculating the value of our harvests

We almost always harvest into standard 2L containers. We do this for reasons that I explore in the chapter on harvesting. Fortuitously though it also provides an easy way to keep track of how much we've harvested.

All packed and ready for the kids to collect

All packed and ready for the kids to collect

Years ago I laboriously estimated the value of the food we harvested, using prices for the equivalent organic supermarket produce. At the same time I added up all of the 2L harvest containers we packed, in the same period. I then divided one by the other and we came up with a value of £2.50 for each container.

Now the value is clearly too high for a container of spinach and too low for a container of cherry tomatoes, but that's the beauty of the system. It's incredibly easy and it averages out over a year.

Mixed brassica flowers in 2L containers

Mixed brassica flowers in 2L containers

As a cross check I've taken a look at about a half a dozen veg box schemes and looked at what they include, and compared them to what we would provide for the same value. In almost all cases we are about right, regardless of the time of year. Bear in mind that all of our veg is local too, whereas most veg box schemes import a lot of veg in winter and early spring.

<aside> 💡 It's worth pointing out that we can take this very simplistic approach because we are not selling our surplus produce, we are giving it a way, but it's proved to be a great way to compare what we produce from year to year.


Calculating the number of meals we harvest

I realised that I could use the same simple system to estimate the number of meals we produce. I just multiply the number of boxes by two. Debbie and I eat about 2.5 allotment meals a day, so a total of five, in winter it's four and in summer it's six. In total, in 2020, we ate 1953 boxes, which works out at a 2L box providing 1 meal for one person.

Salads in 2L containers, I eat one of these a day

Salads in 2L containers, I eat one of these a day