The main rock gardens are laid out on a south-facing slope and are sheltered from the elements, allowing a great number of non-hardy species to thrive in a micro-climate. Small waterfalls run down the rock gardens into a pond which is surrounded by royal ferns, marsh marigolds, skunk cabbage, "Gunnera" ("giant rhubarb") and irises. The gardens contain wide range of ornamental trees and shrubs, including Chusan palms, tulip trees, mulberry, dawn redwood, swamp cypress, Chinese dogwood, Adam's laburnum, common walnut, "Oxydendrum arboreum", and various dwarf conifers.