A black blossom on such a beloved old fashioned plant? It’s like a cross between the Adams Family and The Waltons. I see them as curiously beautiful rather than macabre. There is another strain of black hollyhocks available called ‘Blackwatch’ however mine come from the Thomas Jefferson Center for Historic Plants, a great place to find those old fashioned varieties popular in the 18th and 19th centuries.
Most old-fashioned hollyhocks are regarded as biennials meaning that if you sow seeds one year, it takes two growing seasons to get flowers. Sow seeds after the last frost date in spring. They prefer full sun and humus rich, well-drained soil. Using the color black in the garden can be a challenge, but it is at the same time a nice accent and is a quick way to add depth to your color combinations.