Garden Shop calculator

How much does your garden grow?

With over 80% of UK households having access to a garden of some kind, it’s no surprise that gardening is such a popular pastime.  Digging up- in- or -over, delighting at a new bloom of flowering colour or evicting slugs; there’s always something to do, and the benefits of being out and about include boons to mental and physical health, as well as providing food and fun.

Gardening is undoubtedly great, and it’s not as solitary a pastime as might be thought. Even if you’re not sharing tea down at the allotment, you have companions around, above and underneath your boots.  Worms shifting soil, spiders harvesting the local mosquitoes, woodlice turning splinters to compost – and insects, going from flower to flower on their pollinating business.  We all know that bees (and others!) are needed to help make many fruits and vegetables, but how much they do for each individual garden varies greatly by what plants are being grown.

Apples – for example – really need pollinators, since their pollen is heavy, doesn’t get wind-distributed well, and the flowers don’t fertilise themselves.  Tomatoes can set fruits without insect help, through wind disturbance and self-compatibility, but still produce a greater yield of fruit if there has been a helping tarsus or two.  Whereas if you mostly grow lettuce, or self-pollinating peas, then your garden bees aren’t going to be much involved in your salad.

So – as both a gardener and an entomologist – I’m interested in how much garden pollinators contribute to our own home-growing success.  Firstly, because it’s interesting, and secondly because it helps to illustrate why making space for that patch of wildflowers, or leaving that old rocket to bolt in a corner, is potentially really beneficial for the gardener as well as the bees.

Thus, the ‘Garden Shop’ calculator was born!

This is a simple spreadsheet that you can use to record your garden harvests.  It has categories for most UK crops (they are pretty broad categories), and you can record in grams, ounces or counts of individual produce.  The spreadsheet will then calculate for you:

  • How much it would have cost you to buy that produce in a supermarket *
    = The ‘total yield’ value.
  • What proportion of that value is directly a result of insect pollination **
    = The ‘bee yield’ value.
* based on online prices from Waitrose, Sainsburys, and Abel & Cole, 2018.
** Pollination requirements of fruit and vegetables are taken primarily from Carreck and Williams (1998), Corbet et al., (1991) and Klein et al., (2007).

the Garden Shop calculator

You can download the calculator from the link above.  Note that the file may open in ‘protected view’ when you’ve downloaded it – this is because it has come from an internet location.  This can causes validation errors with newer versions of Office (see the Microsoft Support Page on these errors). The file should be fine, although do give it a quick scan with your virus-checker if you’re uncertain! Re-save it to your computer to get rid of the error.

If you are happy with sending the form back to me when you have completed it (which would be fantastic) then please submit an email address I can contact you on.  I will email out a reminder at the end of November – February.  The list will be deleted after that and I will not share these email addresses with anyone else. (Or you can just send me the sheet back without a reminder.)


Carreck, N. and Williams, I., 1998. The economic value of bees in the UK. Bee world, 79(3), pp.115-123.

Corbet, S.A., Williams, I.H. and Osborne, J.L., 1991. Bees and the pollination of crops and wild flowers in the European Community. Bee world, 72(2), pp.47-59.

Klein, A.M., Vaissiere, B.E., Cane, J.H., Steffan-Dewenter, I., Cunningham, S.A., Kremen, C. and Tscharntke, T., 2007. Importance of pollinators in changing landscapes for world crops. Proceedings of the Royal Society of London B: Biological Sciences, 274(1608), pp.303-313.