Think of your healing garden as a work of art or a poem. When you design your garden, try to include a feeling of rhythm for the viewer. Just as a catchy musical piece has a repeating chorus and satisfying beat, or in a poem you can hear alliteration or repeating rhymes, in your healing garden add repeated groups of plants and thoughtful vertical interest in the plant heights.
In Fig 1 above you can see repetition of the grey foliaged Senecio together with the smaller grey Santolina. The clipped balls of grey add structure to the garden design. In Fig 2. the glossy leaved Ligularia is planted in several bold groups while the slender trunked Cordyine is repeated. Your eye tends to move between the groups as you seek out similar textures. There is also pleasing vertical interest from the low ground-huggers, up the slender trunks and across the the medium sized clumps. The variation in texture also creates interest and drama.
Fig 3. shows how the eye moves along the horizontal layers of concrete blocks topped by the small leafed divaricated ground cover, with explosions of bold subtropicals popping up at intervals. Nice and dramatic!