The garden was established in 1978-79 as an outdoor classroom for the study of plants.
The outdoor classroom will be complete in Spring 2013.
Families can also picnic at the lake and an outdoor classroom is available for use.
"We could use it for an outdoor classroom, like a living laboratory."
The school has 2 floors and 9 outdoor portable classrooms.
Now she wanted her pupils to discover them for themselves in the much bigger, outdoor classroom.
The garden is also used as an outdoor classroom.
There is an outdoor classroom which is used for a range of activities.
About 10,000 students visit the outdoor classroom each year.
He says it would turn his outdoor classroom into a museum.