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When to Plant Zucchini in Grant County, OK

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Grant County, Oklahoma is in USDA Zone 6b. The average last spring frost is April 11 and the first fall frost is October 27, giving you a growing season of approximately 199 days.

At an elevation of 564 feet, Grant County receives approximately 25.7 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Zucchini during the growing season.

Grant County, OK (Zone 6b) Moderate season
199 days
Last Spring Frost April 11
199 growing days
First Fall Frost October 27

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Feb 27 Transplant: Apr 17 🍅 Harvest: Jun 5 – Jul 31
Recommended (50%) ✓ Fits season (80 days to spare)
Start indoors: Mar 7 Transplant: Apr 25 🍅 Harvest: Jun 13 – Aug 8
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 19 Transplant: May 7 🍅 Harvest: Jun 25 – Aug 20

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
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 973 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Zucchini needs ~879 GDD — county provides 3,333 GDD Excellent fit

Zucchini Planting Timeline โ€” Grant County, OK

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 โ€“ Mar 21
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 18 Apr 18 โ€“ May 9
Harvest June 13 Jun 13 โ€“ Aug 8

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
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

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

199 days

Growing Tips for Grant County

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Zucchini in Grant County, OK?

Grant County is in Zone 6b with an average last frost of April 11. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, OK?

Grant County, Oklahoma is in USDA Hardiness Zone 6b. The average last spring frost is April 11 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grant County gardeners in Zone 6b 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 Grant County, OK. Local conditions may vary. Last updated: April 2026.