'Sooty' Sweet William;
or, Black Dianthus
The salability of black flowers causes a lot of "fudging" on the part of marketeers, so that a deep burgundy or maroon dianthus gets marketed as black. Dianthus barbatus nigriscens assuredly is not black, but it is lovely.
We had a packet of seeds for the cultivar 'Sooty.' It's best to start them indoors in trays or outdoors in coldframes, but I just scattered the seeds in a rather dry sun garden, not sure they would grow without any care at all. When sewn right into a garden, it is best done in autumn before first frost, but it can also be done very early in spring after last frost. I scattered the few seeds in Spring, thinly covering them with soil.
As a biennial or tender perennial, it might not be in the garden any great length of time, unless (as is possible) it self-seeds. The first year's foliage will be evergreen right through the following winter, & that first year it will bloom August through November at least. Ours bloomed continuously through frosty mornings & one snowstorm right up to January! The second year flowers will be starting much earlier, by late spring, but the plant probably won't make it through a second winter. To its favor, unlike some biennials that bloom only in their second year, Black Dianthus does bloom the first year even from seed.
Had the seeds been placed somewhere that was not quite so radically a low-maintenance garden, the seedlings would have been so numerous, forming such a thick groundcover about a foot in height, that they would need thinning out. But because we just scattered the seed & ignored them, the resulting patch required no thinning.
'Sooty' wants full sun, but will do well enough in partial shade. Butterflies & bees like the fragrant blooms, & they make good cut flowers. Besides the maroon flowers & red stems, it also has slender green leaves that mature to a shimmering metallic mahagony, making for one of the most unique of all Sweet Williams.
The common name "Sweet William" is after Prince William Augustus, Duke of Cumberland (1721-1765). His extreme cruelty at Battle of Culloden Moor broke the Jacobite rebellion once & for all. He showed not the slightest mercy to the survivors, & followed up his victory with a three-month reign of terror as his soldiers raided the countryside slaughtering even women, children, & the elderly. He thereafter acquired the epithet William the Butcher. Only in England was he ever regarded as Sweet William; he is to this day Stinking Billy in Scotland.