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When to Plant Sunflower in USDA Zone 7b

Zone 7b Zone 7b June

This month in Zone 7b

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 7b.

Avg. last frost April 6
Avg. first frost October 29
  1. Bring in the sunflower

    If you can't use it all right away, check the food-preservation section of your planner.

July will be here before you know it — start on
  • First harvests: sunflower
Get your free Zone 7b 2026 Planting Guide →

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

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.

Annual Blooms in Summer Pollinator-friendly Good for cutting
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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 February 25 Feb 25 – Mar 11
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 18 Mar 18 – Apr 8
Bloom June 10 Jun 10 – Sep 30

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Bloom
July Bloom
August Bloom
September Bloom
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.

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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

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 Spacing24 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 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans
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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 7b?

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

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 – September 30. 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 Cucumbers, Squash, Corn, Tomatoes. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Zone 7b Garden Planner — Free

A 22-page printable planner tailored to Zone 7b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

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.