The Environment Agency has been working for two years to eradicate giant hogweed at the Denver Complex.
The invasive plant, which can grow to more than 8ft tall, is toxic to humans and had largely taken over a piece of land next to the River Ouse.
Coming into contact with the sap or tiny hairs the cow parsley-like plant produces can result in blisters, rashes and uncomfortable swellings.
In 2019 the Environment Agency started its mission to clear the land and stop the non-native plant spreading to nearby arable land.
The site was cleared of thousands of plants with a specialist remote controlled mower on a day in January when the plant stems were completely sap free.
Once finished, the mower had to be thoroughly cleaned to ensure there were no seeds trapped within it, removing the risk of them being transported to other sites.
Giant hogweed seeds remain viable in the seed bank for up to five years so regular visits throughout 2019 to treat the newly germinated seeds with herbicide was necessary.
Last year, a small number of giant hogweed seeds were still present at the site and required treatment.
Now, the site has been completely transformed from an infested piece of land to one rich in biodiversity.
Darren Noble, of the Environment Agency who led on the giant hogweed removal, said: “It is great to see what we have achieved on this site.
“The hogweed was well established and was starting to spread further, but we stopped that and have completely transformed the area.”
Giant hogweed was introduced to the UK in the 19th century and can now be found throughout most of the country especially on river banks where the seeds are transported by water.