What are the best plants for improving soil structure in marble boxes?

Marble boxes can add elegance to any garden, but maintaining healthy soil within them is crucial for plant growth. Certain plants are particularly effective at improving soil structure, ensuring better aeration, drainage, and nutrient retention. Legumes like clover and beans fix nitrogen, enriching the soil naturally. Deep-rooted plants such as comfrey and daikon radish break up compacted soil, promoting better water infiltration. Cover crops like oats and buckwheat prevent erosion and add organic matter. Herbs like yarrow and chamomile also enhance soil microbiology. By choosing these plants, you can create a thriving, sustainable marble box garden with robust soil health.