They need to be set 4 to 5 inches apart to produce healthy, long-lasting flowers. Nigellas don't need any support. To harvest Black Cumin, pick each pod as it turns yellow. Dry in batches in the sun. Use a catch cloth or bag to catch the seeds as the pods split, then strain the seeds to remove chaff.
Black cumin has a strong flavor, resembling fennel.
Grind the seeds and use as you would pepper in seasoning, but test first. Seeds may be sown outside in the spring. Don't sow them too thickly, however, because they will not flourish if overcrowded. They will need to be thinned 4 to 5 inches apart. These plants can easily be cultivated in a greenhouse that has a night temperature of 45 to 50 degrees.