Arranging historic plants in an outdoor plant box can transform your garden into a timeless masterpiece. Start by selecting plants that were popular in the era you wish to emulate, such as Victorian-era roses or medieval herbs. Group plants by height and growth habits, placing taller species at the back and trailing varieties near the edges. Use complementary colors and textures to create visual interest, and ensure proper spacing to allow for growth. Incorporate historical gardening techniques, like companion planting, to enhance plant health. Finally, add vintage-inspired accessories, such as wrought-iron labels, to complete the nostalgic charm. This approach not only honors history but also creates a stunning, cohesive display.