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When to plant Bachelor's Button in Marion County County,

The best window to plant Bachelor's Button in Marion County County, is March 13–April 3, when soil warms to 50°F. Last frost typically hits April 10; first frost October 19. A second sowing from September 7 to September 21 extends the harvest into fall.

When to Plant Bachelor's Button in Marion County, IL

Marion County, Illinois Zone 6b June

Marion County, Illinois gardeners: here's your June plan

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Basket week: bachelor's button

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

A few tasks this June that'll pay off in July
  • First harvests: bachelor's button

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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.

Marion County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 964 feet, Marion County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Bachelor's Button during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Marion County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Feb 22 Transplant: Apr 5 🌸 Bloom: Jun 7 – Aug 30
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🌸 Bloom: Jun 12 – Sep 4
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Mar 9 Transplant: Apr 20 🌸 Bloom: Jun 22 – Sep 14

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Marion County

How your county's soil matches Bachelor's Button's growing requirements.

Soil pH

Your soil pH (6.1–7.0) is within Bachelor's Button's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Marion County is excellent for Bachelor's Button — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Bachelor's Button.

Organic Matter

Organic matter is excellent (4.4%) — Bachelor's Button will thrive.

How to Plant Bachelor's Button

0.3"
Planting Depth
12"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Succession Planting Bachelor's Button

3
successive plantings in your 192-day season

Sow every 6.9 weeks. Last sowing by Jul 21 to harvest before frost.

For a dedicated fall crop, sow by Sep 07.

Bachelor's Button Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Bachelor's Button

Bachelor's Button needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Bachelor's Button Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 5" 0" ✅ Rainfall sufficient
Jun 2.2" 5.2" 0" ✅ Rainfall sufficient
Jul 2.2" 3.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 3.1" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

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

Bachelor's Button Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Bachelor's Button needs ~1,256 GDD — county provides 3,216 GDD Excellent fit

Bachelor's Button Planting Timeline — Marion County, IL

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 13 Mar 13 – Apr 3
Bloom June 12 Jun 12 – Sep 4
Fall Sowing September 7 Sep 7 – Sep 21

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 Direct Sow
May
June Bloom
July Bloom
August Bloom
September Fall Sowing Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Marion County

Growing Tips for Bachelor's Button in Marion County

Direct sow Bachelor's Button outdoors after April 10 in Marion County when soil has warmed and frost danger has passed.

Common pests for Bachelor's Button in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Marion County, IL?

Marion County is in Zone 6b with an average last frost of April 10. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marion County, IL?

Marion County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

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

In Marion County County, , plant Bachelor's Button after the last frost (around April 10) and before the first frost (around October 19). Best results when soil holds above 50°F.

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

Marion County 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 Marion County County's climate?

Yes — Bachelor's Button grows well in Marion County County's temperate climate. Marion County County averages a 192-day frost-free season, with last frost around April 10 and first frost around October 19.

🌱

Your Marion County Garden Planner — Free

A 22-page printable planner built for Marion 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 Marion County, IL. 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.