Creating a thriving gum garden in outdoor plant boxes requires selecting the right plants that can withstand varying conditions while adding aesthetic appeal. Here are some of the best plants to consider for your gum garden:

1. Succulents (e.g., Aloe Vera, Echeveria): These drought-resistant plants are perfect for gum gardens, requiring minimal water and care. Their unique shapes and colors add visual interest.

2. Lavender: Known for its fragrant blooms and resilience, lavender thrives in well-drained soil and full sun, making it ideal for outdoor plant boxes.

3. Rosemary: This hardy herb not only adds flavor to dishes but also thrives in dry conditions, making it a great choice for gum gardens.

4. Agave: With its striking architectural form, agave is a low-maintenance plant that excels in arid environments.

5. Sedum (Stonecrop): A versatile ground cover, sedum is drought-tolerant and comes in various colors, perfect for adding texture to your garden.

For optimal results, ensure your plant boxes have proper drainage and use a sandy or gritty soil mix to mimic natural gum garden conditions. Regular pruning and occasional fertilization will keep your plants healthy and vibrant.

By choosing these plants, you can create a stunning, low-maintenance gum garden in your outdoor plant boxes that thrives year-round.