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When to Plant Bachelor's Button in USDA Zone 2b

Zone 2b Zone 2b June

Your June game plan for Zone 2b

Each item below is timed to Zone 2b's frost dates and soil temperatures. Skip nothing, stress about nothing.

Want it on paper? Download your Zone 2b planting guide →

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.

In Zone 2b, the average last spring frost is around May 22 and the first fall frost is around September 10, giving you a growing season of approximately 111 days.

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Zone 2b Short season
111 days
Last Spring Frost May 22
111 growing days
First Fall Frost September 10

Bachelor's Button Planting Timeline — Zone 2b

Where Is USDA Zone 2b?

The map below highlights the states that contain Zone 2b. Click any state to see the Bachelor's Button planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Bachelor's Button Planting Calendar — Zone 2b

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 22 May 22 – Jun 12
Bloom July 24 Jul 24 – Sep 11

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Bloom
August Bloom
September Bloom
October
November
December

Free Zone 2b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 2b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

Days to Maturity

60–90 days

Soil pH

6 – 7.5

Zone Temperature Range

-45°F to -40°F average annual minimum

Growing Season

111 days (Zone 2b average)

Planting Specifications

Planting Depth0.3 inches
Plant Spacing12 inches apart
Row Spacing12 inches between rows

Succession Planting Bachelor's Button in Zone 2b

2
successive plantings in Zone 2b's ~111-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Bachelor's Button in Zone 2b

Zone 2b has a short growing season (~111 days). Start Bachelor's Button indoors early and use season-extension techniques like row covers and cold frames.

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

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Recommended for Your Garden

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LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

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Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

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Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

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Frequently Asked Questions

When should I plant Bachelor's Button in Zone 2b?

In Zone 2b, plan your Bachelor's Button planting around the average last frost date of May 22. Start seeds indoors around March 27. Direct sow outdoors around May 22. Transplant seedlings around May 22.

Can Bachelor's Button grow in Zone 2b?

Yes, Bachelor's Button can grow well in Zone 2b, hardy in USDA zones 2a through 11b. Zone 2b has a growing season of approximately 111 days, which is sufficient for Bachelor's Button (60-90 days to maturity).

When can I harvest Bachelor's Button in Zone 2b?

In Zone 2b, expect to harvest Bachelor's Button from July 24 – September 11. Bachelor's Button takes 60-90 days from planting to harvest.

What is the last frost date for Zone 2b?

The average last spring frost in Zone 2b is around May 22, and the first fall frost is around September 10. This gives a growing season of approximately 111 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Bachelor's Button?

Good companion plants for Bachelor's Button include Wheat, Grains, Tomatoes, Vegetables. These companions can help with pest control, pollination, and nutrient sharing.

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Your Zone 2b Garden Planner — Free

A 22-page printable planner tailored to Zone 2b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.