Gone Up In My Estimation

A riot of nasturtiums in my polytunnel

The art of estimating is crucial to the small-scale market gardener.


First there's the estimating that happens before the growing season begins. Plans have been drawn up as to which beds will have which veg growing in them. From that it's possible to work out the quantity of crops in total that will be produced from each, based on average yield per area for each type of veg. The next stage is to figure out when exactly those crops are expected to be harvested, across how many weeks. I end up with a beautiful spreadsheet that shows how many customer portions of each veg I will expect in my weekly harvest, for each month of the year.

Most of that veg will be going to the Green Isle Growers veg bag scheme, but not all. I make a version that's applicable to the scheme only, and share it with the group, as do the other growers. We make a combined spreadsheet so we know what the whole group can provide to the scheme, and then whittle it down through discussion to what would fit into fifty customer bags per week.

Sweetcorn in the polytunnel

The next estimating task comes once the scheme starts in June. Every Monday morning I have to assess exactly how many portions of each veg I can provide to the scheme on Wednesday. In an ideal world of course this would be the same as in the aforementioned plan but the unpredictable weather and the onslaught of pests makes it less than ideal. These figures are sent to the person doing the weekly ordering for the scheme (this year, it's me!), who may take all of it or just some of it depending on what's needed to fill the bags with a good variety of veg and fruit. It's vital to get these numbers right - if I overestimate how much I can supply, the scheme will suffer if I can't supply it.

And the final estimating comes at harvesting time, on Tuesday evening and Wednesday morning. I have to judge how much of each crop to pick that will constitute the right number of portions so I don't over-harvest and be left with more than I am allowed to sell to the scheme.

I don't always get these estimations right of course! I've been short of mange tout twice so far, having overestimated what I had, but luckily Ann had some extra that she could supply in place. But the more I estimate the easier it becomes. At least, that's the theory.