Direct seed outdoors once soil has warmed up. Sow 2 seeds 1 cm. deep every 15 cm and thin to one plant per 15 cm. in rows 1 m. apart. Can also be started indoors 5-7 weeks before last frost.  Sow seed 1 cm. deep, firm soil and water lightly. Plant transplants out at 22-30 cm spacing in full sun. Not picky about soil type. Deadhead for blooms until frost, but leave some to go to seed for volunteers next season. Cosmos looks after itself—and the B-3s (bees, butterflies, bugs)