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When to Plant Rutabaga in Columbia County, WA

Rutabagas are a cross between turnips and cabbage, producing large yellow-fleshed roots with a sweet, mild flavor. They are excellent mashed, roasted, or in stews.

Columbia County, Washington is in USDA Zone 6b. The average last spring frost is April 28 and the first fall frost is October 11, giving you a growing season of approximately 166 days.

At an elevation of 3,157 feet, Columbia County receives approximately 21.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Rutabaga during the growing season.

Columbia County, WA (Zone 6b) Moderate season
166 days
Last Spring Frost April 28
166 growing days
First Fall Frost October 11

Columbia County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Apr 18 🍅 Harvest: Jul 11 – Aug 15
Recommended (50%) ✓ Fits season (47 days to spare)
Transplant: Apr 28 🍅 Harvest: Jul 21 – Aug 25
Safe Start (90%) ✓ Fits season (43 days to spare)
Transplant: May 18 🍅 Harvest: Aug 10 – Sep 14

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
0.5″/week
Watering frequency 1-2 times/week
Season total 677 gal / 100 sq ft
Rutabaga needs ~1,575 GDD — county provides 2,905 GDD Excellent fit

Rutabaga Planting Timeline โ€” Columbia County, WA

Rutabaga Planting Calendar

Activity When Date Range
Direct Sow April 14 Apr 14 โ€“ May 5
Fall Sowing August 2 Aug 2 โ€“ Aug 16
Harvest July 7 Jul 7 โ€“ Aug 11

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow
June โ€”
July Harvest
August Fall Sowing 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

80โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

166 days

Growing Tips for Columbia County

Direct sow in early summer for fall harvest. Thin seedlings to 6-8 inches apart. Flavor improves significantly after a few light frosts.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Rutabaga in Columbia County, WA?

Columbia County is in Zone 6b with an average last frost of April 28. Plan your Rutabaga planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Columbia County, WA?

Columbia County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is April 28 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

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