Blog

When to Plant Corn in Whatcom County, WA

Corn

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.

Whatcom County, Washington is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 386 feet, Whatcom County receives approximately 49 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Corn during the growing season.

Whatcom County, WA (Zone 8a) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29

Whatcom County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

How Much Corn to Grow

1-2 ears
Average yield per plant
15
Plants per person
30 sq ft
Space per person

For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In Whatcom County's 206-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Corn Planting Timeline — Whatcom County, WA

Corn Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 8a

📆 Growing Season

206 days in Whatcom County

Growing Tips for Whatcom 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Whatcom County, WA?

Whatcom County is in Zone 8a with an average last frost of April 6. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Whatcom County, WA?

Whatcom County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is October 29.

🌱

Your Whatcom County Garden Planner — Free

A 22-page printable planner built for Whatcom County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.