Nigella is a dual-purpose cutting flower — the intricate blue, white, or pink blooms surrounded by feathery bracts are beautiful fresh, and the inflated seed pods that follow are among the most ornamental of any annual, lasting for months in dried arrangements. Direct sow in very early spring (it germinates in cool soil) or in autumn for spring bloom. It dislikes transplanting.
For fresh cutting, harvest when the flowers are fully open. For seed pods, leave on the plant until the pods are fully inflated and beginning to turn papery; cut and hang to dry upside-down in a warm, airy space. Both stages are useful — nigella earns its space twice over.
Aphids
Clusters of small soft insects on new growth and flower buds.
Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.