When to Plant Sunflower in USDA Zone 8b
Your June gardening checklist
We've pulled the most time-sensitive tasks for Zone 8b this June and put them front and centre. Tackle them in order.
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Start harvesting sunflower
If you can't use it all right away, check the food-preservation section of your planner.
Coming up in July — start thinking about
- 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 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.
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.
Sunflower Planting Calendar — Zone 8b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 4 | Feb 4 – Feb 18 |
| Transplant Outdoors | February 11 | Feb 11 – Feb 25 |
| Direct Sow | February 11 | Feb 11 – Mar 4 |
| Bloom | May 6 | May 6 – Sep 23 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Direct Sow |
| April | — |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| 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.
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
15°F to 20°F average annual minimum
Growing Season
276 days (Zone 8b average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 18 inches apart |
| Row Spacing | 24 inches between rows |
Succession Planting Sunflower in Zone 8b
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Sunflower in Zone 8b
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
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
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 8b?
In Zone 8b, plan your Sunflower planting around the average last frost date of February 25. Start seeds indoors around February 4. Direct sow outdoors around February 11. Transplant seedlings around February 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 6 – September 23. 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 Cucumbers, Squash, Corn, Tomatoes. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 8b Garden Planner — Free
A 22-page printable planner tailored to Zone 8b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.