The nursery has been selling plants to the public since the 1970s

Cornwall Fire Brigade was alerted to the fire in the early hours of Wednesday morning.

Two fire engines from Lostwithiel are at the scene, together with two from Bodmin, and water carriers from Bodmin and Newquay.

Clarence House said Prince Charles, who has just returned from a visit to the US, would be upset by the news.

There's not much we're going to be able to do with it Tracey Wilson, Duchy of Cornwall Nursery

A spokeswoman said the Duke of Cornwall would be informed about the fire.

She said he was very familiar with the set-up and had recently made a private visit during the summer to meet staff and see how things were going.

Witnesses reported hearing an explosion in the tea rooms. An investigation into the cause of the fire has started.

Staff said they hoped to have the nursery up and running again by the weekend.

The nursery, which is part of the original Duchy of Cornwall estate, is situated across the valley from Restormel Castle, the home of the first Duke of Cornwall.

Nursery development

In the 1960s, it was used for forest tree production and started to sell plants to the public in 1974. It is now one of the largest and most respected garden nurseries in the region.

Tracey Wilson, the manager of the nursery, told BBC News she was devastated by the fire.

She said: "The next step I suppose in all honesty is to demolish it, because there's not much we're going to be able to do with it.