When to Plant Sunflower in USDA Zone 6b
Your July planting checklist for Zone 6b
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 6b.
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Collect sunflower at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
August prep starts now
- First harvests: sunflower
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 6b, the average last spring frost is around April 3 and the first fall frost is around October 25, giving you a growing season of approximately 205 days.
Sunflower Planting Timeline — Zone 6b
Where Is USDA Zone 6b?
The map below highlights the states that contain Zone 6b. Click any state to see the Sunflower planting schedule for that location.
Sunflower Planting Calendar — Zone 6b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Bloom | June 26 | Jun 26 – Sep 25 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Free Zone 6b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6b with start dates, transplant windows, and harvest times.
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 0°F average annual minimum
Growing Season
205 days (Zone 6b average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 18 inches apart |
| Row Spacing | 24 inches between rows |
Succession Planting Sunflower in Zone 6b
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Sunflower in Zone 6b
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
The Gardener's Encyclopedia to Companion Planting
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- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
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Saving Sunflower Seeds
Recommended for Your Garden
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Keep your garden organized with durable, weather-resistant plant labels.
Related Plants
Sunflower in Other Zones
Sunflower by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Sunflower in Zone 6b?
In Zone 6b, plan your Sunflower planting around the average last frost date of April 3. Start seeds indoors around March 13. Direct sow outdoors around April 3. Transplant seedlings around April 3.
Can Sunflower grow in Zone 6b?
Yes, Sunflower can grow well in Zone 6b, hardy in USDA zones 2a through 11b. Zone 6b has a growing season of approximately 205 days, which is sufficient for Sunflower (70-100 days to maturity).
When can I harvest Sunflower in Zone 6b?
In Zone 6b, expect to harvest Sunflower from June 26 – September 25. Sunflower takes 70-100 days from planting to harvest.
What is the last frost date for Zone 6b?
The average last spring frost in Zone 6b is around April 3, and the first fall frost is around October 25. This gives a growing season of approximately 205 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 6b Garden Planner — Free
A 22-page printable planner tailored to Zone 6b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.