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When to Plant Corn in Clatsop County, OR

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

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 Corn during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Corn 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 (91 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 3 – Jul 29
Recommended (50%) ✓ Fits season (87 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 9
Safe Start (90%) ✓ Fits season (95 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 2 – Aug 27

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Corn needs ~1,160 GDD — county provides 2,987 GDD Excellent fit

Corn Planting Timeline โ€” Clatsop County, OR

Corn Planting Calendar

Activity When Date Range
Direct Sow April 19 Apr 19 โ€“ May 10
Harvest June 21 Jun 21 โ€“ Aug 16

Plant 1" deep ยท 12" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May 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

60โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8b

Growing Season

206 days

Growing Tips for Clatsop County

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Level Up Your Garden

Frequently Asked Questions

When should I plant Corn in Clatsop County, OR?

Clatsop County is in Zone 8b with an average last frost of April 12. Plan your Corn 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.

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