Crushed volcanic rock is being held up as the key to growing giant sized organic fruit and vegetables.

Strawberries the size of apples and onions the size of footballs are now set to be studied by scientists in Scotland.

Researchers at Glasgow university will be studying the organic fruit and vegetables, grown by Scottish couple Cameron and Moira Thomson in Blairgowrie.

The Thomson’s claimed the secret behind their giant produce is simply down to remineralising their ground with volcanic rock dust.

The couple founded a charitable trust, the Sustainable Ecological Eart Regeneration Centre, planting 64 trial plots of land to carry out research into organic gardening.

The land was spread with crushed up volcanic rock and Cameron Thomson said the land was transformed from ‘infertile, poorly drained upland grazing.’

He said a late planting of potatoes resulted in a bumper crop, with the vegetables the size of mangoes.

“They had less water in them and last so much longer than anything you would ever have seen before.”

The scientists are now studying the Thomson’s produce as part of a three-year project.