Orange Daylily

Hemerocallis fulva is the daylily that has escaped from more gardens than any other, and the reason is the same reason it is useful: it is close to impossible to kill. Thick fleshy roots, arching strap foliage and a long succession of orange trumpets, each open for a single day, make it a mass-planting workhorse.
It earns its place where the ground is difficult, holding banks, verges and dry slopes that are hard to irrigate and harder still to mow.
The Orange Daylily is the plant to specify when a difficult slope has to be covered, held and forgotten about.