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When to Plant Pumpkin in Clatsop County, OR

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

Clatsop County, Oregon is in USDA Zone 8b. The average last spring frost is April 12 and the first fall frost is November 4, giving you a growing season of approximately 206 days.

At an elevation of 412 feet, Clatsop County receives approximately 54.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Pumpkin during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Pumpkin root diseases.

Clatsop County, OR (Zone 8b) Long season
206 days
Last Spring Frost April 12
206 growing days
First Fall Frost November 4

Clatsop County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Mar 15 Transplant: Apr 26 🍅 Harvest: Jul 26 – Sep 13
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Aug 13 – Oct 1

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.

Soil Compatibility in Clatsop County

How your county's soil matches Pumpkin's growing requirements.

Soil pH

Your soil pH (5.6โ€“6.7) overlaps with Pumpkin's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Clatsop County is excellent for Pumpkin โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) โ€” Pumpkin will thrive.

How to Plant Pumpkin

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 361 gal / 100 sq ft

Monthly Watering Guide for Pumpkin

Pumpkin needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Pumpkin Needs Rainfall You Supplement Action
Jan โ€” 8.4" 0" โ„๏ธ Dormant
Feb โ€” 5.2" 0" โ„๏ธ Dormant
Mar โ€” 4.8" 0" โ„๏ธ Dormant
Apr 5.6" 3.8" 1.8" ๐Ÿ’ง Light watering
May 5.6" 3.6" 2" ๐Ÿ’ง Light watering
Jun 5.6" 2.1" 3.5" ๐Ÿšฟ Regular watering
Jul 5.6" 0.9" 4.7" ๐Ÿšฟ Regular watering
Aug 5.6" 1.1" 4.5" ๐Ÿšฟ Regular watering
Sep 5.6" 2.4" 3.2" ๐Ÿšฟ Regular watering
Oct 5.6" 4.2" 1.4" ๐Ÿ’ง Light watering
Nov 5.6" 8.4" 0" โœ… Rainfall sufficient
Dec โ€” 9.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Clatsop County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Pumpkin Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Pumpkin needs ~1,486 GDD — county provides 2,987 GDD Excellent fit

Pumpkin Planting Timeline โ€” Clatsop County, OR

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 โ€“ Mar 29
Transplant Outdoors April 26 Apr 26 โ€“ May 10
Direct Sow April 19 Apr 19 โ€“ May 10
Harvest July 26 Jul 26 โ€“ Sep 13

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

85โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

206 days in Clatsop County

Growing Tips for Pumpkin in Clatsop County

Direct sow Pumpkin outdoors after April 12 in Clatsop County when soil has warmed and frost danger has passed.

Common pests for Pumpkin in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pumpkin in Clatsop County, OR?

Clatsop County is in Zone 8b with an average last frost of April 12. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clatsop County, OR?

Clatsop County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 12 and first fall frost is November 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clatsop County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Clatsop County, OR. Local conditions may vary. Last updated: April 2026.