It is no secret that the humble potato regularly goes on epic treks to reach Scottish supermarkets, but neither is it something we are encouraged to contemplate as the plastic bags of cut-price tatties thud into our trolley - the small type showing the country of origin is inevitably tucked away in a corner.

Yet light bulbs have been flashing furiously above the heads of pupils at Kildrum Primary in Cumbernauld. They have their own abundant vegetable garden, and the eureka moment comes at harvest time after having learnt about the far-flung origins of so much modern-day produce - such as potatoes from Israel.

The school vegetable garden, once an uninspiring spot dominated by bushes, was created around five years ago and has become an institution. Each September, the vegetables are sold to parents and the proceeds put back into the garden.

The potential for learning about healthy eating and enterprise are clear, but in recent months the garden has taken on another dimension. Last year, P6 pupils learned about ecological footprints - in other words, the amount of waste, food, transport, energy and water required to maintain their daily routine. The work was done as part of the Schools’ Global Footprint Project, with help from North Lanarkshire Council and WWF Scotland.

Pupils kept food diaries, calculated the “food footprint” of school dinners, re-used plastic bags, and looked at how to reduce food waste and packaging in the school.

They also planted and looked after vegetable seeds with the help of Kenny MacGregor from the Cumbernauld Allotments Society.

Now in P7, the pupils involved not only harvest their own produce, but cook, eat and sell it.

“The project has been fantastic and really inspired the children,” says teacher Karen McBride. “We reduced waste in the dinner hall by establishing a composting scheme, encouraging children to eat locally grown produce after investigating the air miles of foods they normally eat, as well as getting them to eat more vegetables.

“Parents have bought our vegetables and the composting bins are full to overflowing because the staff and pupils are eating more fruit. This year, the kids were really looking forward to making their own soups from what they’ve grown.”

The garden is extremely popular among pupils of all ages, many of whom live in flats. “The children are all very enthusiastic,” says Myra Lindsay, the headteacher. “We’ll have children who go out during lunch and ask: ‘What can I do in the garden?’ It’s amazing.”

That enthusiasm has now also taken on an ecological dimension - as seen in lunch boxes.

Although the school’s overall ecological footprint had not changed a great deal when measured recently - partly because health and safety rules meant produce from the garden could not be used for school dinners - Mrs McBride thinks each pupil’s footprint will have changed significantly, because their attitude to the food they bring with them is now so different.

Parents report that pupils are scrutinising where food comes from when out shopping. They are also taking home what they do not eat in school, rather than throwing it out.

Meanwhile, produce from the vegetable garden has been finding its way into packed lunches - a return journey that is more food metres than food miles.

FOOD MILES?

Some of the fruit and vegetables grown at Kildrum Primary - and the origin of the same produce in one Scottish supermarket.

Beans: Kenya

Beetroot: UK

Broccoli: UK

Cauliflower: unspecified

Courgettes: Spain

Garlic: Spain

Onions: SpainUK

Potatoes: ScotlandUK

Pumpkins: UK

Spinach: UK

Tomatoes: HollandItalyUK

Based on produce checked in the Byres Road Somerfield store, Glasgow, on Wednesday, October 10.