TV gardening expert Alan Titchmarsh, pictured left, has agreed to open a £600,000 tree house complex that is taking shape in the New Forest.

The timber-built study centre is the brainchild of the Countryside Education Trust (CET). It is being built in woodland near the National Motor Museum, Beaulieu.

Teenagers taking part in environmental studies will be able to move from one classroom to another using a walkway 16ft above the ground. About 10,000 youngsters a year will use the complex, which is due to be officially opened in September.

Titchmarsh began his TV career on the long-running BBC 1 show Nationwide and went on to present Gardeners' World.

He also hosted the hugely popular Ground Force, which gave run-down gardens a new lease of life.