In the Back-to-Back category, 'A Quiet Corner' by Hertfordshire's Anna Murphy and Sarah Jarman won gold and best in category.
In the Year of Light category, conceptual gardens champion the International Year of Light, which is a United Nations initiative to highlight the vital role that light plays in providing solutions to global challenges.
Helen Elks-Smith and Kate Hart's 'Reflecting Photonics' won gold as did Leon Davis' 'Quantum of Light', and Sharon Hockenhull's 'Light Catcher', was awarded best in category.
About Sharon Hockenhull's design, an RHS judge commented: "What an exciting and compelling interpretation of a complex concept with gorgeous planting juxtaposed with a dramatic backdrop."
Jackie Knight's 'Nature's Reflection' was awarded best water garden with a striking rock and water composition, crafted from natural materials. Preston City Council won best exhibit in the RHS National Flower Bed Competition and Sally Parkinson's 'The Tiny Plant Company' was awarded Best Blooming Bed.
In the Floral Marquee, Southfield Nurseries were awarded best exhibit for their display of cacti and succulents, while Cheshire Area NAFAs was awarded best exhibit in the Floral Design Studio. Best exhibit in the National Plant Societies and Plant Heritage Marquee went to National Sweet Pea Society.