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When to Plant Celosia in USDA Zone 3b

Zone 3b Zone 3b June

Your June gardening checklist

Welcome to June in Zone 3b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 16
Avg. first frost September 22
  1. Transplant celosia outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Scatter celosia into prepared beds

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

  3. Indoor seed-starting week for celosia

    These need a head start before your last frost (May 16). Sow into cells now so you're ready to transplant in a few weeks.

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Celosia (Celosia argentea) encompasses the vivid cockscomb (cristata) and feathery plumed (plumosa) types that explode with color in summer heat. Drought-tolerant and disease-resistant, they thrive in the hottest parts of the season and produce long-lasting blooms both in the garden and as cut or dried flowers. A reliable filler in sunny annual beds.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

Annual Blooms in Summer Pollinator-friendly Good for cutting
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Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Celosia Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Celosia planting schedule for that location.

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

Celosia Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 31 May 31 – Jun 21
Bloom August 2 Aug 2 – Oct 11

Plant 0.1" deep · 9" 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
August Bloom
September Bloom
October Bloom
November
December

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b 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

Zone Temperature Range

-35°F to -30°F average annual minimum

Growing Season

135 days (Zone 3b average)

Planting Specifications

Planting Depth0.1 inches
Plant Spacing9 inches apart
Row Spacing12 inches between rows

Succession Planting Celosia in Zone 3b

2
successive plantings in Zone 3b's ~135-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Celosia in Zone 3b

Zone 3b has a short growing season (~135 days). Start Celosia indoors early and use season-extension techniques like row covers and cold frames.

Start seeds indoors 4–6 weeks before last frost, or direct-sow after soil warms above 60°F. Does not transplant well from large pots — sow in small cells or direct-sow. Needs full sun and warm soil; cold stress causes stunting. Pinch first bloom to encourage branching. Water at the base; wet foliage encourages fungal issues. Excellent dried flower — harvest before seeds set for the best color retention.

Companion Planting

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Saving Celosia Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

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

🔥
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.

Related Plants

Frequently Asked Questions

When should I plant Celosia in Zone 3b?

In Zone 3b, plan your Celosia planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 31. Transplant seedlings around May 31.

Can Celosia grow in Zone 3b?

Yes, Celosia can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Celosia (60-90 days to maturity).

When can I harvest Celosia in Zone 3b?

In Zone 3b, expect to harvest Celosia from August 2 – October 11. Celosia takes 60-90 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Celosia?

Good companion plants for Celosia include Marigolds, Zinnias, Portulaca, Vinca. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Zone 3b Garden Planner — Free

A 22-page printable planner tailored to Zone 3b. 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.