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When to Plant Bachelor's Button in Douglas 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.

Douglas County, Oregon is in USDA Zone 8b. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.

At an elevation of 377 feet, Douglas County receives approximately 52.6 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.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Douglas County, OR (Zone 8b) Long season
215 days
Last Spring Frost April 4
215 growing days
First Fall Frost November 5

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

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 8.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 2.3" 2" 💧 Light watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 1" 3.3" 🚿 Regular watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 7.6" 0" ✅ Rainfall sufficient
Dec 7.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Douglas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Bachelor's Button Planting Timeline — Douglas County, OR

Bachelor's Button Planting Calendar

Activity When Date Range
Transplant Outdoors March 14 Mar 14 – Mar 28
Direct Sow February 14 Feb 14 – Mar 7
Bloom May 16 May 16 – Sep 12
Fall Sowing September 10 Sep 10 – Sep 24

Plant 0.3" deep · 12" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March Transplant Outdoors Direct Sow
April
May Bloom
June Bloom
July Bloom
August 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

215 days in Douglas County

Growing Tips for Douglas 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 →

Frequently Asked Questions

When should I plant Bachelor's Button in Douglas County, OR?

Douglas County is in Zone 8b with an average last frost of April 4. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, OR?

Douglas County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 4 and first fall frost is November 5.

🌱

Your Douglas County Garden Planner — Free

A 22-page printable planner built for Douglas 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Douglas County, OR. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.