When to Plant Sunflower in USDA Zone 2b
Zone 2b gardeners: here's your July plan
July is a pivotal month for Zone 2b gardens. Focus on these tasks first and you'll set up the rest of the season for success.
Download your personalised Zone 2b planting plan →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 2b, the average last spring frost is around May 22 and the first fall frost is around September 10, giving you a growing season of approximately 111 days.
Sunflower Planting Timeline — Zone 2b
Where Is USDA Zone 2b?
The map below highlights the states that contain Zone 2b. Click any state to see the Sunflower planting schedule for that location.
Sunflower Planting Calendar — Zone 2b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 1 | May 1 – May 15 |
| Transplant Outdoors | June 5 | Jun 5 – Jun 19 |
| Direct Sow | June 5 | Jun 5 – Jun 26 |
| Bloom | August 28 | Aug 28 – Oct 16 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Free Zone 2b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 2b 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
-45°F to -40°F average annual minimum
Growing Season
111 days (Zone 2b average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 18 inches apart |
| Row Spacing | 24 inches between rows |
Growing Tips for Sunflower in Zone 2b
Zone 2b has a short growing season (~111 days). Start Sunflower indoors early and use season-extension techniques like row covers and cold frames.
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
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Saving Sunflower Seeds
Recommended for Your Garden
Full-spectrum LED lights for starting seeds indoors when daylight is limited.
Warm soil for faster germination of heat-loving crops like tomatoes and peppers.
Protect plants from frost, wind, and pests while letting light and water through.
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 2b?
In Zone 2b, plan your Sunflower planting around the average last frost date of May 22. Start seeds indoors around May 1. Direct sow outdoors around June 5. Transplant seedlings around June 5.
Can Sunflower grow in Zone 2b?
Yes, Sunflower can grow well in Zone 2b, hardy in USDA zones 2a through 11b. Zone 2b has a growing season of approximately 111 days, which is sufficient for Sunflower (70-100 days to maturity).
When can I harvest Sunflower in Zone 2b?
In Zone 2b, expect to harvest Sunflower from August 28 – October 16. Sunflower takes 70-100 days from planting to harvest.
What is the last frost date for Zone 2b?
The average last spring frost in Zone 2b is around May 22, and the first fall frost is around September 10. This gives a growing season of approximately 111 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 2b Garden Planner — Free
A 22-page printable planner tailored to Zone 2b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.