Blog

When to Plant Sunflower in USDA Zone 7b

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 7b, the average last spring frost is around March 18 and the first fall frost is around November 8, giving you a growing season of approximately 235 days.

Zone 7b Long season
235 days
Last Spring Frost March 18
235 growing days
First Fall Frost November 8

Sunflower Planting Timeline — Zone 7b

Where Is USDA Zone 7b?

The map below highlights the states that contain Zone 7b. 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 7b

Activity When Date Range
Start Indoors January 28 Jan 28 – Feb 11
Transplant Outdoors April 1 Apr 1 – Apr 15
Direct Sow March 25 Mar 25 – Apr 15
Harvest June 10 Jun 10 – Jul 29

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

Month-by-Month Timeline

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

Free Zone 7b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 7b with start dates, transplant windows, and harvest times.

Get My Free Calendar →

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

5°F to 10°F average annual minimum

Growing Season

235 days (Zone 7b average)

Planting Specifications

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

Succession Planting Sunflower in Zone 7b

3
successive plantings in Zone 7b's ~235-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Sunflower in Zone 7b

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

🌱
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 7b?

In Zone 7b, plan your Sunflower planting around the average last frost date of March 18. Start seeds indoors around January 28. Direct sow outdoors around March 25. Transplant seedlings around April 1.

Can Sunflower grow in Zone 7b?

Yes, Sunflower can grow well in Zone 7b, hardy in USDA zones 2a through 11b. Zone 7b has a growing season of approximately 235 days, which is sufficient for Sunflower (70-100 days to maturity).

When can I harvest Sunflower in Zone 7b?

In Zone 7b, expect to harvest Sunflower from June 10 – July 29. Sunflower takes 70-100 days from planting to harvest.

What is the last frost date for Zone 7b?

The average last spring frost in Zone 7b is around March 18, and the first fall frost is around November 8. This gives a growing season of approximately 235 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 7b, track your crops, and plan your garden season from seed to harvest.

Get Your Free Garden Planner →

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.