SO many plants make rounded mounds of flower and foliage. Borders made up solely from these plants can resemble a rumpled duvet after a night out. This is why vertical spikes and spires are so necessary visually. The verticals link earth to sky, and break up the monotony of all those humps and lumps.
Many spikes and spires take up little ground space, because the flowerheads oftenflower and pollination takes place. This is an accidental by-product of nectar and pollen gathering.
