Annual flower
Bachelors Button plant profile
Centaurea cyanus
An annual flower for full sun.
Last updated .
When to plant
When to plant Bachelors Button
Start seeds indoors
8 weeks before your last spring frost to 6 weeks before your last spring frost
Growing conditions
- Sun
- Full sun
- Soil pH
- 6 to 8
- Lifecycle
- Annual
Common problems
Watch for these
Also watch for: needs staking when tall, mealybugs, self seeding.
Evidence trail
Evidence behind this profile
Original extension and institutional publications behind the planting, care, and safety facts on this page.
- Centaurea cyanus (Bachelor's Button, Cornflower)
North Carolina Extension Gardener Plant Toolbox (NC State Extension). Supports indoor seed-starting timing (direct) and planting season (direct). Checked 2026-06-18.
- Toxic and Non-Toxic Plants: Cornflower (Centaurea cyanus) entry
ASPCA Animal Poison Control Center. Supports pet-safety verdicts for dogs and cats. Checked 2026-07-18.