Bananas
Rotting organic matter may not sound delicious, but there is nothing that should increase the productivity of an allotment more. And rotting bananas are a particular treat. Not only does compost improve the soil, but it can act as a mulch to help retain moisture and warmth. One of the first things Spuds and I did when we got our patch was to install a compost bin, and we will be adding another in the coming months.