Used often as a groundcover or an edging plant, liriope is popular for good reason. It stays green year-round in many climates, produces pretty blue or white flowers, and is about as tough a plant as you’ll hope to meet. Its dense tufts of almost-evergreen, broadly grassy leaves are often striped. Stiff stems bear tight spikes of tiny blue or white bells, similar to those of grape hyacinth. It is best protected from drying winds in rich, well-drained soil that retains moisture.