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When to Plant Sunflower in Greer County, OK

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.

Greer County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 4, giving you a growing season of approximately 212 days.

At an elevation of 602 feet, Greer County receives approximately 34.5 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Sunflower during the growing season.

Greer County, OK (Zone 7b) Long season
212 days
Last Spring Frost April 6
212 growing days
First Fall Frost November 4

Greer County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🍅 Harvest: Jun 20 – Aug 8
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 29 – Aug 17
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 8 – Aug 26

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Sunflower needs ~1,615 GDD — county provides 4,028 GDD Excellent fit

Sunflower Planting Timeline โ€” Greer County, OK

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 โ€“ Mar 2
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest June 29 Jun 29 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7b

Growing Season

212 days

Growing Tips for Greer County

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

Frequently Asked Questions

When should I plant Sunflower in Greer County, OK?

Greer County is in Zone 7b with an average last frost of April 6. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Greer County, OK?

Greer County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 4.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Greer County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Greer County, OK. Local conditions may vary. Last updated: April 2026.