Cameron Brow has volunteered to play the part of a seed and he steps into the middle of the circle of children. He has not noticed the watering can.
We are at Harlow Carr, the Royal Horticultural Society's garden on the outskirts of Harrogate. The Year 2 children from Bramley St Peter's Church of England Primary School, Leeds, are about to see how a seed germinates.
Cameron kneels down and a plastic sheet decorated with sunflowers is placed over him. Debbie Handslip, who is Harlow Carr's schools and family events officer, asks what a seed needs to grow. She encourages suggestions from the children. Wrong answers are not dismissed, but welcomed as part of the fun.
Water is poured from the watering can over the plastic sheet. Cameron now has water, oxygen and warmth. He is stirring and everyone giggles, but a seed needs something more to become tall and strong. Debbie suggests cornflakes, but everyone says "no". A box of compost is handed to Saffron Bedford and she pours it over the sheet. Underneath, Cameron is now growing briskly. Debbie explains that Cameron will eventually produce seeds of his own. She pulls back the sheet to reveal Cameron clutching a bunch of flowers. There are gasps of delight. Cameron is, of course, clean and dry.
"They will remember this for a long time," says Delphine Roberts, who is the children's teacher. "It's the sort of inspiration you pray for.
Sometimes it comes, but more often it doesn't."
Debbie wants to ensure that children will look more carefully at the environment and explore things they would normally walk past. Her language is fresh, exciting and funny. We are on a journey of discovery, walking around the gardens, looking at leaves and unusual trees, meeting an artist who is creating willow sculptures and seeing the world's smallest Christmas tree.
In Harlow Carr's Study Centre the children each plant two seeds in a pot to take home and they make a leaf sculpture from clay. Debbie demonstrates how they should take one plant out of the pot when it is large enough. After lunch there is a hunt beneath trees for tiny creatures. Again Debbie's language is inspiring and enthusiastic. We are exploring and hunting, but we are careful. "We don't dig with the trowels; we scrape them gently along the surface," she says. "We don't dig, because we don't want to harm the animals living lower down".
Lewis Willshire has found a wriggling little thing with lots of legs and he is singing his delight: "Aren't we lucky? Aren't we lucky?" He doesn't know what it is. "I'll ask Debbie, she'll know," he says, and off he trots.
Then it is time for some weaving. In a woodland glade there are permanent, raised weaving frames made of plastic netting. Older children have woven minibeast homes using a frame of chicken wire. Today's children are in groups and they are weaving using natural materials to make a spider's web.
A plastic spider is placed on each frame. A smaller plastic creature represents the spider's lunch and the weaving begins.
Twigs, dead grass, leaves and the occasional bird's feather are gathered and bought to the frames. Within the 10-minute time limit there are some remarkable webs. We join hands to make a ring and walk slowly round the frames, admiring everyone's handiwork.
l The RHS has gardens at Hyde Hall in mid-Essex, Rosemoor in Devon, and Wisley in Surrey. All have educational facilities and admission for school groups is free.
Contact the RHS for details of Schools Membership Scheme Tel: 020 7821 3000 www.rhs.org.uk