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When to Plant Pumpkin in Coconino County, AZ

Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Coconino County, Arizona is in USDA Zone 5b. The average last spring frost is May 28 and the first fall frost is September 27, giving you a growing season of approximately 122 days.

At an elevation of 7,869 feet, Coconino County receives approximately 13.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Pumpkin may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Pumpkin will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Pumpkin successfully. Mulch heavily to conserve soil moisture.

Coconino County, AZ (Zone 5b) Short season
122 days
Last Spring Frost May 28
122 growing days
First Fall Frost September 27

Coconino County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 13 Transplant: May 1 🍅 Harvest: Jul 31 – Sep 18
Recommended (50%) ✗ May not fit
Start indoors: Apr 23 Transplant: Jun 11 🍅 Harvest: Sep 10 – Oct 29
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jul 8 🍅 Harvest: Oct 7 – Nov 25

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
1.0″/week
Watering frequency 2-3 times/week
Season total 1,070 gal / 100 sq ft
Drought risk

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

Pumpkin needs ~2,255 GDD — county provides 2,684 GDD Good fit

Pumpkin Planting Timeline โ€” Coconino County, AZ

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 โ€“ May 7
Transplant Outdoors June 11 Jun 11 โ€“ Jun 25
Direct Sow June 4 Jun 4 โ€“ Jun 25
Harvest September 10 Sep 10 โ€“ Oct 29

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“120 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

122 days

Growing Tips for Coconino County

Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Pumpkin in Coconino County, AZ?

Coconino County is in Zone 5b with an average last frost of May 28. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coconino County, AZ?

Coconino County, Arizona is in USDA Hardiness Zone 5b. The average last spring frost is May 28 and first fall frost is September 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coconino County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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