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When to Plant Sunflower in USDA Zone 8a

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 8a, the average last spring frost is around March 8 and the first fall frost is around November 18, giving you a growing season of approximately 255 days.

Zone 8a Long season
255 days
Last Spring Frost March 8
255 growing days
First Fall Frost November 18

Sunflower Planting Timeline — Zone 8a

Where Is USDA Zone 8a?

The map below highlights the states that contain Zone 8a. 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 8a

Activity When Date Range
Start Indoors January 18 Jan 18 – Feb 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 31 May 31 – Jul 19

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

Month-by-Month Timeline

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

Free Zone 8a Planting Calendar PDF

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

10°F to 15°F average annual minimum

Growing Season

255 days (Zone 8a average)

Planting Specifications

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

Succession Planting Sunflower in Zone 8a

4
successive plantings in Zone 8a's ~255-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Sunflower in Zone 8a

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

Level Up Your Garden

Saving Sunflower Seeds

Recommended for Your Garden

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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 8a?

In Zone 8a, plan your Sunflower planting around the average last frost date of March 8. Start seeds indoors around January 18. Direct sow outdoors around March 15. Transplant seedlings around March 22.

Can Sunflower grow in Zone 8a?

Yes, Sunflower can grow well in Zone 8a, hardy in USDA zones 2a through 11b. Zone 8a has a growing season of approximately 255 days, which is sufficient for Sunflower (70-100 days to maturity).

When can I harvest Sunflower in Zone 8a?

In Zone 8a, expect to harvest Sunflower from May 31 – July 19. Sunflower takes 70-100 days from planting to harvest.

What is the last frost date for Zone 8a?

The average last spring frost in Zone 8a is around March 8, and the first fall frost is around November 18. This gives a growing season of approximately 255 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.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 8a, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

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.