Pupils at Rossett Acre Primary School spent last week excitedly ploughing and planting a new patch, where they hoped to grow fruit and vegetables including broad beans, potatoes, and peas.

On their return to school after the Bank Holiday weekend, teachers were horrified to discover that all their hard work had been destroyed.

Julia Askey, co-ordinator of the project and foundation stage phase leader, said the caretaker had discovered the damage first thing on Tuesday morning, and had alerted the police immediately.

She said the entire vegetable patch area had been ripped up, and the trellises to grow herbs had been torn down: "It was done to enhance our outdoors area, and we had a platform with trellises on, but it's all been broken and vandalised. Ripped apart, completely broken. It's irreparable," she said.

"We have a lot of people that come into the playground after hours, we have people after school that ride their bikes across the playground. It's been an on-going problem, and we've had problems in the past.

"They are trespassing and they have been asked lots of times to go. They used to be able to ride off the platform and I think it's a protest because we have spoiled their fun."

The project had been part of Yorkshire Water's Green Fingers Campaign, where volunteers are sent out to schools across Yorkshire to dig and plant gardens and outdoor spaces for children.

The children had been looking forward to seeing the plants grow and tasting their own vegetables, but the school will not be able to replace the trellises, which were a gift from Yorkshire Water.

Mrs Askey said: "Our caretaker is going to try and rectify the damage as best as he can, but I doubt we will be able to put the trellis back because we can't afford it.

"It's the children that are suffering because of this mindless vandalism."