Joint owners Les Prethero and Neil Usher, who bought the centre this year, said the roofs had caved in on four 82ft by 32ft glass greenhouses.
It survived previous harsh winters, including the great winter of 1962/63.Prethero said: "It is devastating. The sheer weight of the snow piled on the roofs has caused the aluminum frames to buckle.
"As a result, the roofs have collapsed, showering all our stock with glass, sheeting and snow.
"The garden centre has gone. The greenhouses are beyond repair. They will have to be rebuilt.
"The majority of stock inside them, Christmas trees, decorations, plants and compost has also been destroyed.
"We will be closed for quite some months."No-one was hurt.