A wood burning boiler has saved the jobs of nursery staff and cut heating bills by 85 per cent.

Ravensworth Nurseries was forced to seek an alternative to oil when the price soared from 27p to 50p a litre.

Between October last year and May it cost £50 an hour - more than £100,000 in total - to heat its three acres of glasshouses near Richmond, North Yorkshire.

Doug Bradbrook, who co-founded the company, said: "We employ 34 people from local villages and if we had not changed, we would have had no option but to have a big rationalisation. We could not have grown higher-temperature plants any longer."

The biomass boiler uses up to four tonnes of wood chips a night to protect plants from frost.

A shredder handles 12 to 15 tonnes of pallets an hour, which would normally have gone to landfill.

When the oil price peaked it cost the nursery more than £1 to grow each poinsettia.

Delighted with the new system, Mr Bradbrook is critical of the Government which constantly encourages companies to go green.

He said: "We found there were no grants available and on top of that, we have to pay £900 a year for an environmental licence from the local authority and £1,200 a year for the boiler to be tested, even though it is completely carbon free."

He is asking the National Farmers' Union to investigate.

Mr Bradbrook and Bill Hannah founded the nursery 40 years ago.