‘Black Swan’ is too gorgeous to tuck away into a collage of other flowers, with its intricate, finely cut petals as dark as cabernet. Sow it along a path you frequent or in a large container where you can admire its richly colored 3″–5″ semi-double blossoms on graceful, curved, swan-like necks, while bees savor the nectar. Harvest them for exquisite bouquets.