The earliest three-dimensional flower bed effect

Quick answer：

The earliest three-dimensional flower bed effect refers to the earliest forms of ornamental flower arrangements that create a sense of depth and dimension. These early examples date back to ancient civilizations such as the Egyptians, Greeks, and Romans. They utilized artistic techniques such as raised beds, layering of plants with varying heights, and the use of hedges and topiaries to create a visually appealing and immersive garden space.