The stage-building complex which is due to be complete in summer, is being built in Purfleet on an old agricultural site dating back more than 300 years.
A derelict walled garden the size of five tennis courts is being decked out by Norfolk nursery British Wild Flower Plants, with cowslips, daisies and viper's bugloss. It will contain a performance space, Tudor knot garden and kitchen garden for older varieties such as white carrots. An "opera border" of perennials punctuated by Agapanthus and red hot pokers will denote musical high notes near a restored orchard.
Beyond the walled garden will be a reinstated downland meadow with thousands of harebells, bell flowers, hoary plantains, traditional hedgerows and woven hazel.
Landscape masterplanner Clive McDonnell Landscape Design is working with historic gardens expert Caroline Holmes and contractor Gavin Jones.