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When to Plant Bachelor's Button in USDA Zone 9b

Zone 9b Zone 9b June

June in Zone 9b — your action list

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 February 14
Avg. first frost December 4
Get your Zone 9b-specific planner by email →

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 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Bachelor's Button Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. 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 9b

Activity When Date Range
Transplant Outdoors December 21 Dec 21 – Jan 4
Direct Sow November 23 Nov 23 – Dec 14
Bloom February 15 Feb 15 – Jun 7
Fall Sowing October 11 Oct 11 – Oct 25

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b 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

25°F to 30°F average annual minimum

Growing Season

329 days (Zone 9b average)

Planting Specifications

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

Succession Planting Bachelor's Button in Zone 9b

6
successive plantings in Zone 9b's ~329-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Bachelor's Button in Zone 9b

Zone 9b offers a long growing season (~329 days). You can plant Bachelor's Button earlier and may get multiple harvests.

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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Saving Bachelor's Button Seeds

Recommended for Your Garden

☀️
Garden Shade Cloth $15-35

Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

Related Plants

Frequently Asked Questions

When should I plant Bachelor's Button in Zone 9b?

In Zone 9b, plan your Bachelor's Button planting around the average last frost date of January 25. Direct sow outdoors around November 23. Transplant seedlings around December 21.

Can Bachelor's Button grow in Zone 9b?

Yes, Bachelor's Button can grow well in Zone 9b, hardy in USDA zones 2a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Bachelor's Button (60-90 days to maturity).

When can I harvest Bachelor's Button in Zone 9b?

In Zone 9b, expect to harvest Bachelor's Button from February 15 – June 7. Bachelor's Button takes 60-90 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 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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A 22-page printable planner tailored to Zone 9b. 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.