This year’s exceptionally dry weather, which led to drought being declared across most of the country, will mean the Christmas staple is around half its maximum size.
The lack of water in the summer, the driest on record for the UK, means sprouts have not been able to grow to their full potential, said Richard Mowbray of the UK Brassica Growers Association.
“Normal supermarket specifications are between 18mm to 40mm. This year’s batch will be at the smaller end of that,” he said.
Mr Mowbray said Christmas diners shouldn’t expect any drop in quality from their smaller sprouts, which taste sweeter than their larger counterparts. “They used to be sold as a premium product, as baby sprouts,” he said.
This year’s heatwave and drought saw temperatures hit a new UK high of 40.3C in Coningsby, Lincolnshire, which produces around 60 per cent of the country’s brassicas, the vegetable family to which sprouts belong .
Some 25 per cent of all sprouts in the UK are sold over the Christmas period, although only half of the 750 million sprouts produced a year are eaten, according to the University of Warwick.
The British are Europe’s biggest consumers of sprouts, which have been traced back to Brussels in the 13th century, and were named by the French in the 1700s.
Sub zero temperatures this winter are also making the picking tricky, said Chris Gedney of TH Clements, in Boston, Lincolnshire, which typically harvests 192 million sprouts each year.
"It's challenging. We had the heat wave, and now we have the really low temperatures - the timing could not be worse,” he told the BBC.
Mr Gedney said: "Once it gets below about -3C (27C) it starts to get really challenging for both our operators and machinery."
He praised his hardy workforce, adding: "A lot of our work still needs to be done by hand. There are some tough people out there."
There are expected to be plenty of sprouts to go round however, even if you might need a few more on your plate.
Mr Gedney said: "We're looking at lighter yields and shorter stalks but we're confident people will have Brussels sprouts on their dinner plates this Christmas."
Climate change is expected to bring more heatwaves, and made this year’s drought 20 times more likely, according to a study by scientists at the World Weather Attribution service.
This year’s frost could also make Brussels sprouts sweeter this year, according to researchers at the University of Warwick, which is working on genetic modifications to make the sometimes controversial Christmas dinner vegetable more palatable.
“Sulphur is responsible for the bitter sprout taste. As we age, we lose tastebuds, which can make them more palatable – potentially why adults who hated sprouts as children now embrace them in seasonal dishes,” research fellow Lauren Chappell said. “What’s more, frosty weather converts bitter starches into sugars, leading to sweeter tasting sprouts (hence the logic behind grandparents remarking they ‘won’t eat sprouts until the first frost’).”