Unseasonably warm temperatures have led to "chunky" asparagus spears sprouting nearly a foot tall in Herefordshire.
Grower Chris Chinn, of Ross on Wye, said he was "absolutely astonished" to see the crop, usually harvested in early March, two months earlier.
But after the warmest December on record, he said it was "not that surprising".
The Met Office confirmed on Tuesday December was the wettest and warmest since records began in 1910.
Temperatures were about 7.9C (46F).
Mr Chinn, whose 1,000-acre family-run farm supplies Marks and Spencer with the vegetable, told BBC News his asparagus grows in temperatures above 6C (42F), and they normally expect to see the first spears by Valentine's Day.
"It's been the warmest December on record and this asparagus will grow over about 6C and if you look back at records over December, it was more or less 6C, including in the night time, so it's not that surprising I guess?," he said.
He said he came to check on the crop this week before sealing the polytunnels, but was stunned to see the fully-grown spears.
"It's just emerged through January and presumably started growing in December.
"I definitely didn't expect to see it.
"We came up here to check the tunnels had weathered the storms over Christmas... and thought we'd seal the doors down as normally we're harvesting in early March, so we're absolutely astonished."
The traditional start of the season is 23 April and runs through to mid-June.
Mr Chinn said the crops would reach chefs around the country this weekend and if the warm spell stays, they could start to appear in supermarkets in the coming weeks.
However, he said the predicted cold snap next week could slow growth, but would not ruin the crop.