Biennial. Zone 2. Caryophyllaceae. Dianthus barbatus originated in the mountains of southern Europe.
‘Sooty’ is often billed as the “black” Sweet William, but in reality it is a deep, rich crimson, with nicely contrasting pure white stamens. Though ‘Sooty’ is often described as “new and improved”, in reality it is almost indistinguishable in my experience from the venerable English heirloom variety, ‘Dunnett’s Deep Crimson’, introduced in the late 1800s.
Many heads of clove-fragranced, velvety crimson flowers are produced in midsummer of the plant’s second year. Foliage shows a distinctive dark red blush, as do stems, particularly at the leaf joints. ‘Sooty’ tends not to be as tall or as substantial in form as many of the other traditional Sweet Williams, reaching only 12 to 18 inches tall, and proving occasionally rather lax in habit.
‘Sooty’ blooms for a fairly extended time. You may get a few flowers in autumn of its first year, but the best show comes in year two, when the cluster-heads bristling with dark-blushed, sharply pointed, modified leaflets unfold their blooms from early June and well into summer. For continued flower production, promptly deadhead when the clusters finally fade, or harvest at peak perfection for bouquets.
Something of a curiousity in the garden, though a very pleasant one.
I must confess that I have sometimes found ‘Sooty’ a little difficult to place. Self-sown seedlings generally manage to find a niche where they can blend well with their neighbours, but my greatest success with Sweet Williams in general, including ‘Sooty’, was way back when I grew ambitious vegetable gardens, which always included several rows of annual flowers for cutting. For a few years I included “biennial rows” which I planted out in late summer, full of Sweet Williams and Canterbury Bells and their like. With abundant fertility and regular watering, these bloomed the following spring and summer with great vigour, providing armfuls of flowers for arrangements. In the mixed border, fighting it out for growing space among various companions, I find that the Sweet Williams don’t reach such majestic proportions as when treated more as “crop” plants.
A true biennial which may carry on by offsets, but usually by self-seeding, so allow a few bloom heads to mature seed to re-sow.
Sun is best, though light shade is tolerated. Good soil and moisture are appreciated.