“But wait,” you say, “lily of the valley is already prolific enough.” We have a different kind of proliferation here, however. Each individual bell-flower is multiplied into a dense cluster of smaller, cup-shaped blossoms. From a distance, it reads as a double-flowered form, even though it isn’t, botanically speaking. Although moist well-drained soil and semi-shade suit it best, it will adapt to much worse. Modified continental/Maritime/Montane/Mediterranean; N Temperate Region. Zone 4.