Outdoor plant boxes can indeed be attached to walls or fences, offering a versatile and space-saving solution for gardening enthusiasts. Whether you're working with limited yard space or aiming to create a lush vertical garden, wall-mounted or fence-attached plant boxes are a practical choice.

To ensure stability, use sturdy brackets, screws, or hooks designed for outdoor use. Materials like treated wood, metal, or durable plastic are ideal for longevity. Consider the weight of the soil and plants when selecting mounting hardware to prevent sagging or collapse.

For fences, lightweight plant boxes with proper drainage are recommended to avoid water damage. On walls, opt for designs that complement your home's exterior while providing adequate support. With the right setup, outdoor plant boxes can transform any vertical surface into a vibrant green oasis.

Always check local regulations or homeowner association rules before installing permanent fixtures. Happy gardening!