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When to Plant Sunflower in USDA Zone 8b

Zone 8b Zone 8b April

This month in Zone 8b

Here's what deserves your attention in Zone 8b this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost March 5
Avg. first frost November 22
  1. Time to start sunflower inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

May will be here before you know it — start on
  • First harvests: sunflower
Send me my free Zone 8b Planting Guide →

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

In Zone 8b, the average last spring frost is around February 25 and the first fall frost is around November 28, giving you a growing season of approximately 276 days.

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Zone 8b Year-round
276 days
Last Spring Frost February 25
276 growing days
First Fall Frost November 28

Sunflower Planting Timeline — Zone 8b

Where Is USDA Zone 8b?

The map below highlights the states that contain Zone 8b. Click any state to see the Sunflower planting schedule for that location.

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

Sunflower Planting Calendar — Zone 8b

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 4 Mar 4 – Mar 25
Harvest May 20 May 20 – Jul 8

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

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

Free Zone 8b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 8b 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

70–100 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

276 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing18 inches apart
Row Spacing30 inches between rows

Succession Planting Sunflower in Zone

4
successive plantings in Zone 's ~276-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Sunflower in Zone

Zone has a short growing season (~276 days). Start Sunflower indoors early and use season-extension techniques like row covers and cold frames.

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
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Saving Sunflower Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

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

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Sunflower in Zone 8b?

In Zone 8b, plan your Sunflower planting around the average last frost date of February 25. Start seeds indoors around January 7. Direct sow outdoors around March 4. Transplant seedlings around March 11.

Can Sunflower grow in Zone 8b?

Yes, Sunflower can grow well in Zone 8b, hardy in USDA zones 2a through 11b. Zone 8b has a growing season of approximately 276 days, which is sufficient for Sunflower (70-100 days to maturity).

When can I harvest Sunflower in Zone 8b?

In Zone 8b, expect to harvest Sunflower from May 20 – July 8. Sunflower takes 70-100 days from planting to harvest.

What is the last frost date for Zone 8b?

The average last spring frost in Zone 8b is around February 25, and the first fall frost is around November 28. This gives a growing season of approximately 276 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Sunflower?

Good companion plants for Sunflower include Corn, Cucumber, Squash Summer. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. 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: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.