Black Cumin is grown for its wonderful and healing aromatic black seeds that are ground and used like pepper. Feathery plants have bluish-white flowers that are followed by inflated ornamental pods perfect for dried arrangements. Self Seeding Annual. Nigella sativa seed is also known as fennel flower, nutmeg flower, Roman coriander, blackseed or black caraway. Plant seeds outdoors just before the last frost. They will self seed profusely. Prefers average soil and tolerates dry conditions. Remove spent blossoms regularly to prolong blooming.