When to plant Bachelor's Button (Cornflower)
Computed from land-grant Extension planting-window rules (cited below), localized to real ZIP-level median frost dates, not a single national guess. These are national-generic rules by hardiness class; individual state Extension offices layer their own regional adjustment on top (earlier in the Deep South, later in the Upper Midwest). Enter your ZIP for your own dates, or read the four representative locations below.
Planting windows and crop timing here are computed from USDA/NOAA climate data and the university extension sources cited below, not a site visit or soil test. Treat this as a starting point: local conditions vary, and a local nursery or extension office can advise on your exact site. See our full Disclaimer.
Representative timing, by climate band
When to plant Bachelor's Button (Cornflower) in four US climates
Each column is the most nursery-dense location in our directory within that USDA zone band, computed from that location's own real median frost dates, not a made-up example.
| Stage |
Zones 1-5 (cold winters)
Fort Plain, NY |
Zones 6-7 (temperate)
McMinnville, TN |
Zones 8-9 (warm)
Apopka, FL |
Zones 10-13 (hot, frost rare or absent)
Loxahatchee, FL |
|---|---|---|---|---|
| Start seed indoors | Mar 11–Mar 25 | Feb 10–Feb 24 | Dec 30–Jan 13 | – |
| Direct-sow outside | Not available | Not available | Not available | – |
| Transplant outside | Not available | Not available | Not available | – |
| Fall planting | Not available | Not available | Not available | – |
| Expected harvest | Not available | Not available | Not available | – |
Zones 10-13 (hot, frost rare or absent) (Loxahatchee, FL): Frost is rare here (about 359 frost-free days a year); most years see little or no hard freeze. This is a hardy crop. In climates like this one, hardy and semi-hardy crops typically go in during the cooler months (fall through late winter), not on a frost-relative schedule.
Bachelor's button, also called cornflower, is a hardy annual. NC State Extension's Plant Toolbox entry for Centaurea cyanus says seed "should be started indoors 6 to 8 weeks before last frost, or in mild winter climates can be seeded in situ directly outdoors in the fall." Clemson Cooperative Extension's Growing Annuals factsheet (HGIC 1152) corroborates the hardy classification and the fall-seeding option.
Neither source gives an exact week count for a spring direct-sow date, a weeks-before-first-frost figure for the fall option, or a first-bloom day count, so those three fields are blank on this page rather than filled with an estimate.
Bachelor's button is bought and grown almost entirely from seed; sow indoors on the schedule above, or direct-sow outdoors in fall where winters run mild enough.
Frost hardiness
Hardy. Tolerates hard frost. Can go in the ground before the last frost date.
Sourcing notes
Hardy annual: NC State Extension Plant Toolbox states seeds "should be started indoors 6-8 weeks before last frost, or in mild winter climates can be seeded in situ directly outdoors in the fall"; Clemson's Growing Annuals factsheet corroborates a hardy classification with a fall-seeding option. Neither source gives an explicit spring direct-sow week-count, a weeks-before-first-frost figure for the fall option, or a first-bloom day count, so those fields are left blank rather than estimated.
Related crops
Growing zones for this crop
Nurseries near these locations
Sources
- Clemson Cooperative Extension Home & Garden Information Center, Growing Annuals (HGIC 1152) (accessed 2026-08-04)
- NC State Extension Gardener Plant Toolbox, Centaurea cyanus (accessed 2026-08-04)