Grow your own and save £26 a week

I've just completed a project where I received daily press clippings about the retail industry. One day, I received the following:

Grow your own and save £26 a week
Research carried out by the National Society of Allotment and Leisure Gardeners has estimated that allotment holders save almost £1,400 a year by growing their own fruit and vegetables. Amateur gardeners grow 1,642lb of produce a year, which could be sold for £1,564. On average they spend £202 renting their plot and sowing crops, giving a profit or saving of £1,362. This equates to a saving of about £26 from an average family's weekly supermarket shopping bill.
The Daily Telegraph, Date: 20/01/2011, Page: 5 Daily Express, Page: 30(14629035) Metro London, Page: 27(14631978) The Sun, Page: 36(14629566)

This straight away made me think whether we match up to this.

The easiest sums to do are the costs - rent £18, Alton Allotment Association membership £4, seed order £7.80, potatoes £6, IOW garlic £2?, onions tbc. So I estimate total costs, including some further miscellaneous to be about £50 each year.

Savings that we make, well over the summer, we're pretty self sufficient in veg, and don't need to buy any puddings because of the soft fruit (although will buy ice cream, and ingredients to make crumble topping etc). We do still need to buy apples, oranges, grapes and the like for our lunch boxes.

So I guess it is to calculate what we don't spend at the supermarket. Looking at Sainsbury's website, from what we grow, to replace even one of each costs £45, not even taking into account that we try to be good at freezing things/storing. I would guesstimate that food wise there are a good 15 weeks of the year where we supplement very little, this would give at least £750 saved pounds. However, to be honest, growing your own definitely determines what you eat - I'm pretty sure we would not each so much courgette if we didn't grow it!!!!

We also give quite a lot away, particularly rhubarb and runner beans. Sainsburys regularly sell 3 sticks of rhubarb for £1.99, we reckon that we give away probably 30-40 sticks a year - that's worth up to £80, although we generally only receive a cup of tea or something stronger in return! I'm not sure that there is a direct displacement either, although we may all be a few pounds lighter.

So, do I agree with the sums - well no, for two reasons: we're not allowed to sell all our produce, and I doubt farmers receive the amount that the supermarkets sell for, and no way would we add £26 every week to our shopping bill, we'd be bankrupt!