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When to plant Bachelor's Button in Osage County, MO

Osage County sits in USDA Zone 6b. Plant Bachelor's Button between March 9 (after last frost on April 6) and March 30. A second sowing from September 18 to October 2 extends the harvest into fall.

When to Plant Bachelor's Button in Osage County, MO

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.

Osage County, Missouri is in USDA Zone 6b. The average last spring frost is April 6 and the first fall frost is October 30, giving you a growing season of approximately 207 days.

At an elevation of 1,300 feet, Osage County receives approximately 38.7 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.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Osage County, MO (Zone 6b) Long season
207 days
Last Spring Frost April 6
207 growing days
First Fall Frost October 30

Osage County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Bachelor's Button Planting Timeline — Osage County, MO

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors April 6 Apr 6 – Apr 20
Direct Sow March 9 Mar 9 – Mar 30
Bloom June 8 Jun 8 – Aug 31
Fall Sowing September 18 Sep 18 – Oct 2

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors
May
June Bloom
July Bloom
August Bloom
September Fall Sowing
October Fall Sowing
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 6b

📆 Growing Season

207 days in Osage County

Growing Tips for Osage 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 Osage County, MO?

Osage County is in Zone 6b with an average last frost of April 6. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Osage County, MO?

Osage County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 6 and first fall frost is October 30.

When should I plant Bachelor's Button in Osage County, MO?

In Osage County, MO, plant Bachelor's Button after the last frost (around April 6) and before the first frost (around October 30). Best results when soil holds above 50°F.

What growing zone is Osage County, MO for Bachelor's Button?

Osage County sits in USDA Zone 6b. Bachelor's Button grows reliably in zones 2a through 11b, so it's a good fit here.

Can Bachelor's Button grow in Osage County's climate?

Yes — Bachelor's Button grows well in Osage County's temperate climate. Osage County averages a 207-day frost-free season, with last frost around April 6 and first frost around October 30.

🌱

Your Osage County Garden Planner — Free

A 22-page printable planner built for Osage County (Zone 6b). 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 Osage County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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