Wild Mountain Perennial Cornflower seed propagation can seem tricky by some since the germination rate is generally in low 20’s but to grow Centaurea montana from seed in 3-4 weeks is just like any other Centaurea seed really, except for one key detail.
To grow C. montana from seed, sow 8-10 seeds per pot in late Summer to early Winter indoors. Cover with 1/2″ soil & mist to moisten. The key here is Centaurea montana requires darkness to germinate. Cover with dark plastic or one layer of newspaper & maintain 60-70F for germination 17-21 days. Sow direct late Winter to early Spring, 1/2″ deep.
Mountain cornflower likes moist conditions & full sun but will tolerate poor soil & dry conditions. An interesting, easy care, plant & forget perennial wildflower. Loved by bees & left alone by deer & rabbit. Zone 3-8, Native to the mountains of California. Easily grow Centaurea montana from seed naturally, in the right conditions if not deadheaded.