Scotts relaunched Chapelwood, bought from Solus in 2015, for this season but has had to compete with the mildest winter since records began in 1910, with average temperatures four degrees centigrade above normal.
Gardman took much of the business lost in the Scotts-Solus takeover, but brands such as Chapelwood, Gardman and Peckish are seeing a short, sharp peak this week, before milder weather returns. The wild bird food industry is worth more than £200m a year. Some reports suggest sales were about 20 per cent down on an average year.
Gardman said: "Retailers have commented that pre-Christmas sales were slower, however, our sales are stronger than ever and the recent colder weather is definitely providing a further boost to sales."
Meanwhile, one in four primary school children cannot identify a blackbird or robin red breast, a poll has found.
More than half are unable to name three of Britain’s most common garden species – the great tit, starling and chaffinch – while a third of six to ten-year-olds have never fed a bird at home.
Some 72 per cent do not know that a group of crows is known collectively as a ‘murder’, while 17 per cent are unaware that the black-headed gull is one of the most common seabirds in Britain.
Two in five children say they have never seen an owl in real life, while a similar proportion could not identifiy a common sparrow when shown its picture, according to the study for retail chain Wilko.
Wilko pets buyer Neil Fairhurst said children’s knowledge of the natural world seemed to be getting worse with each new generation.
"They seem more interested in watching TV and playing computer games than getting out to enjoy the incredible nature and wildlife available to them."
And a spokesman for the RSPCA, which is asking families to feed wild birds in their gardens, said: "As the weather turns colder it is important to think about what we can do to help our animal friends.
"It is important to preserve the wild bird population of this country and giving them a helping hand in finding food as the weather gets colder is a great way to start.
"Birds can struggle to find food during the winter months so, to help them stay strong over this period, householders can leave out wild bird food for them."
More than half a million people from across Britain are set to take part in the RSPB's Big Garden Birdwatch by counting the birds in their gardens over the weekend of January 30 to 31.