When to Plant Bachelor's Button in Josephine County, OR
Bachelor's Button (Centaurea cyanus), also called cornflower, is a carefree cool-season annual best known for its vivid cobalt-blue flowers — one of the truest blues in the annual garden. It tolerates light frosts, self-seeds prolifically, and thrives in poor to average soils. A traditional cut flower and pollinator magnet, it has been cultivated in gardens for centuries.
Josephine County, Oregon is in USDA Zone 8b. The average last spring frost is April 22 and the first fall frost is October 20, giving you a growing season of approximately 181 days.
At an elevation of 340 feet, Josephine County receives approximately 52.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Bachelor's Button during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Bachelor's Button root diseases.
Josephine County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.2
Drainage
Well Drained
Monthly Watering Guide for Bachelor's Button
Bachelor's Button needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Bachelor's Button Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.4" | 0" | ❄️ Dormant |
| Feb | — | 6.6" | 0" | ❄️ Dormant |
| Mar | — | 6.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Jun | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jul | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Aug | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Oct | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 7.4" | 0" | ❄️ Dormant |
| Dec | — | 8.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Josephine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Bachelor's Button Planting Timeline — Josephine County, OR
Bachelor's Button Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 1 | Apr 1 – Apr 15 |
| Direct Sow | March 4 | Mar 4 – Mar 25 |
| Bloom | June 3 | Jun 3 – Sep 30 |
| Fall Sowing | August 25 | Aug 25 – Sep 8 |
Plant 0.3" deep · 12" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing Bloom |
| September | Fall Sowing Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 8b
📆 Growing Season
181 days in Josephine County
Growing Tips for Josephine County
Direct-sow in early spring as soon as soil can be worked; seeds need a brief cold period for best germination (refrigerate for a few days before planting if spring arrives quickly). In zones 6+, fall-sow for the earliest spring bloom. Thin to 12 inches; do not over-fertilize — too much nitrogen produces foliage at the expense of flowers. Deadhead to prolong blooming or allow self-seeding for a naturalized colony.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Bachelor's Button in Other Locations
Frequently Asked Questions
When should I plant Bachelor's Button in Josephine County, OR?
Josephine County is in Zone 8b with an average last frost of April 22. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.
What planting zone is Josephine County, OR?
Josephine County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 22 and first fall frost is October 20.
Your Josephine County Garden Planner — Free
A 22-page printable planner built for Josephine County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.