I was thinking something like this (hope it works...)

Grape Map

You should be able to plug your postcode in and find your plot/garden/field and stick a pin in it.

Edit: I know I've mentioned the map thing before, but that was individual maps - I think this way it should allow the creation of a collective map so we can see at a glance where everyone is.

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A simple dude trying to grow veg.

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