Some poinsettia growers have cut back on production because of rising fuel bills this season, with more imports expected as a result.
Roundstone Nurseries has called a halt to production of 200,000-plus plants for Sainsbury's and Marks & Spencer and an Asda supplier has cut production by half.
Roundstone managing director Peter Cook said: "The cyclamen programme we replaced poinsettia with is more profitable and poinsettia turned out to be a risky crop. Energy use is very intensive for a number of months and you are a hostage to fortune as to how the market then goes. It is highly unlikely we will revisit that crop (poinsettia)."
One South East nursery that supplies Asda with poinsettias said its fuel prices are up by 30 per cent. "We are doing 50 per cent less. It was 50,000 but we're down to 25,000 because it's such a high-risk crop, so we decided to play it safer. All the costs are going up but sale prices are not necessarily going up."
Peter Eastwood Nurseries is growing two-thirds as many as in 2012 after erecting a smaller glasshouse for its 2013 crop. Owner Peter Eastwood said: "We hope to produce a better product with slightly less heat input." Heat use so far this year is half that of last year, he added.
Roundstone supplies through Double H, whose quality manager Mark Riley said he has upped production partly because Roundstone stopped and because "poinsettia are a little more profitable than some other winter options because the market has stabilised somewhat".
Pinetops director Ian Paton is growing 100,000, the same as in 2012, for Homebase and independents. He said: "There will be a shortfall at some point because a lot of growers can't afford to grow them. It's just the heat crippling us. We're going to get a woodburner as soon as we can, which will make a massive difference."
Heat prices rose 10-15 per cent last year "meaning a lot of growers were getting on the border for whether they were making money or not", Paton added.
Young Plants technical manager and Dummen agent Henrik Nielsen said: "This year there might be 100,000 fewer grown in the UK and one reason is fuel prices. But if growers fit biomass boilers they will grow more."
Coletta & Tyson stopped growing poinsettias in 2010 because its older glass made them uneconomic to heat. Five years ago UK production was between 500,000 and one million plants more than today, said Nielsen, and "imports have made up most of that".
Peter Byrne, general manager at Waitrose supplier Bordon Hill, said: "Energy is a significant cost and it is easy to get caught out. When schedules and prices are agreed in spring, we don't know what the unit energy cost will be for the coming autumn and the weather affects the amount we use, so there is a quite a big risk.
"We are growing a similar quantity to last year but overall I think there will be fewer produced in the UK compared to last year. The gap will probably be filled by imports from Holland."
Hills Brothers director Greg Hill said he is producing slightly more this season for Waitrose, Marks & Spencer and Sainsbury's, but the crop is challenging.
Gert van der Plight, managing director at Dutch supplier Plight Professionals, said he is producing 500,000 with 40 per cent for the UK market, specifically Morrisons. Last year, 10 per cent went to the UK.
Sainsbury's plant technologist Nicola Phillips said: "Our poinsettias are always 100 per cent British and grown in six sites across the UK from the south coast all the way up to Scotland."