A green-fingered grandmother who tends to plant pots and comes along on school trips has said she loves spending time with children because "everything is like an adventure".

Retired secretary Deborah Herbert has been popping into Castle Hill Primary School in Chessington, where her twin grandsons study, for four years.

The 62-year-old brings along her planting seeds, gardening tools and sometimes even her Freedom Pass to accompany little ones on days out.

Mrs Herbert said: "I just love the children's chatter, excitement and freshness - everything is like an adventure. The school just ring me up and say ‘are you free?’ It just keeps me going.

"I’m not ready to be a real retired lady.

"My grandchildren at the moment they don’t mind but I am sure when they get older they won’t want me there. I helped out at Tolworth Girls’ when my daughter went there and the last thing she wanted was me there."

She added her favourite trip with Castle Hill had been a visit to the Petrie Museum of Egyptian Archaeology in Camden when the children were learning about Egyptians.

She said: "I had never heard of the museum or been there so I thoroughly enjoyed it."

The Moor Lane resident, who has lived in the borough for more than 40 years, enjoys yoga, swimming and running in her spare time. She will also be running in Race for Life at the end of the month.

Rebecca Stopford, business manager at Castle Hill, said: "Mrs Herbert is always willing to help out at the drop of a hat. She has been on numerous school trips regardless of whether her grandchildren are in the class or not.

"She has voluntarily been our green fingered gardener for the pots out the front of the school. She has filled them with beautiful flowers and shrubs all at her own cost and comes in to water them.

"Her most recent trip was to the London Eye for the children who had 100 per cent attendance. She was over the moon at being invited to look after the children and was very proud that she didn’t cost the school a penny as she had her freedom and Merlin pass.

"She has walked the children to and from the library and swimming pool in the sun and rain and still comes back for more - a huge thank you from all at Castle Hill."

On being nominated an unsung hero, Mrs Herbert said: "I am quite taken back. I do it because I love doing it. I didn’t think about being nominated - it didn’t occur to me. It is really lovely though."