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When to Plant Bachelor's Button in Forest County, WI

Forest County, Wisconsin Zone 4b June

Your June planting checklist for Forest County, Wisconsin

Each item below is timed to Forest County, Wisconsin's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 20
Avg. first frost September 30
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.5 hrs

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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.

Forest County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 30, giving you a growing season of approximately 133 days.

At an elevation of 556 feet, Forest County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Bachelor's Button to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Forest County, WI (Zone 4b) Short season
133 days
Last Spring Frost May 20
133 growing days
First Fall Frost September 30

Forest County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Mar 27 Transplant: May 15 🌸 Bloom: Jul 17 – Sep 18
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Apr 1 Transplant: May 20 🌸 Bloom: Jul 22 – Sep 23
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Apr 12 Transplant: May 31 🌸 Bloom: Aug 2 – Oct 4

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 Forest County

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Bachelor's Button's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Bachelor's Button will thrive.

How to Plant Bachelor's Button

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

Succession Planting Bachelor's Button

2
successive plantings in your 133-day season

Sow every 6.9 weeks. Last sowing by Jul 02 to harvest before frost.

Bachelor's Button Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.6" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.5" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Forest 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 ~919 GDD — county provides 1,629 GDD Excellent fit

Bachelor's Button Planting Timeline — Forest County, WI

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 6 May 6 – May 27
Bloom July 22 Jul 22 – Sep 23

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors
July Bloom
August Bloom
September 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: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

133 days in Forest County

Growing Tips for Bachelor's Button in Forest County

Direct sow Bachelor's Button outdoors after May 20 in Forest 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 Forest County, WI?

Forest County is in Zone 4b with an average last frost of May 20. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forest County, WI?

Forest County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 30.

🌱

Your Forest County Garden Planner — Free

A 22-page printable planner built for Forest County (Zone 4b). 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 Forest County, WI. 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.