Around 17 million are bought nationally each year, but only 20% are used afterwards and many will be discarded as food waste.
Elmbridge Borough Council says it is keen that people don’t leave unwanted pumpkins in woodlands following social media advice.
The authority says they are not a naturally occurring substance in the UK having been imported from North America.
Pumpkin flesh can cause severe illness in hedgehogs and dumped
food waste has to be cleared by council staff.
The council is asking people to either eat pumpkins once they are finished with or compost them at home.