Lily-of-the-valley is sensational to cut—both foliage and flowers—but it can be a patchy scroffle in the garden. Soil to dry? Too much sun? Who-knows-what bug is hungry? Then the foliage gets brown-edged and chewed-through. And besides, the plant goes dormant in Summer anyway, so even if it does do you the favor of retreating underground, then you're left with a weed-friendly bare patch.
LotV is great for an out-of-the-way spot, where it can be an ankle-biting cutting garden. Or as just a foot or two, here and there, in any garden you need to look at beyond Memorial Day. The plant's sheer persistence even in the less-than-optimal conditions that make it so unattractive, coupled (I guess) with the mooshy-romantic "Lily of The Valley" name, have made the species itself far too popular. Even if it doesn't look quite like you'd hoped, there it is, year after year. And you can still get an adorable bouquet or two from it. Lily of the Valley is one of our most cherished eyesores.
In gardens where you need to look beyond an appealing (to some) name, and bring a frank, clinical, even cynical judgment to bear on if a given plant is really, truly, worth a damn the second after the flowers fade, Lot V doesn't cut the mustard. Unless, that is, you grow this one:

From the moment the leaves spear-up in early Spring, they aren't just the ten-millionth Lily of the Valley leaf in your state. They are
striped, and with rhythm and regularity. And, so to speak, a narrative arc: They start from the same spot at the base of the leaf, and merge into the same spot at the tip of the leaf. It's a controlled performance, with none of the wild-man cavorting of
striated Solomon's Seal.)
The flowers themselves are (I admit) lovely, but they are a bonus not the only thing worth a damn about the entire plant. My colony is still young—I think this is it's third Spring—and I only sprang for three of them to start with. Controlled performances, with narrative arc too, don't come cheap. And it's already clear that, at least for me, this beautiful show isn't from a plant that has any prowess as a groundcover. Yes, the species can colonize so thickly it's a decent (but not great) grondcover. But striped leaves mean a more modest performance. It must take a lot of energy—and should—to bring narrative arc to each and every leaf. So I'll weed my patch of yellow-striped Lot V, and ponder if there's a tinier-still, but much more effective, groundcover it would consent to cohabit with. I need to respond in kind, and bring to it the controlled performance it's bringing to me. The gauntlet is thrown, or at least tossed. Let the games begin.


