But I like a loose, lush look, so I used an asymmetrical scheme that flows around the space and leads the eye to the trellis screen at the end of the garden. After the bones of the space were in place, I began filling and softening it with plants. So I used plants in a range of sizes. I avoided towering monsters and puny plants that got lost, except for a few small pots of specimen plants that I placed as accents. In general, I place heavier, taller plants in back and use mid-sized plants to fill in gaps.
Shorter plants work well in front and around the sides and edges where they can be enjoyed up close.
However, big-leaved plants don't always have to be kept in the background. It's the overall presence and visual weight of the plant that matters. It was a heavy mass at a low height that visually anchored the garden and contrasted with smaller plants surrounding it. Layered container plantings simulate the look of a lush border. The author varies the heights of plants by using inverted pots and other makeshift risers.