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When to Plant Rutabaga in Benton County, OR

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.

Benton County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.

At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Rutabaga during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rutabaga root diseases.

Benton County, OR (Zone 8a) Moderate season
199 days
Last Spring Frost April 14
199 growing days
First Fall Frost October 30

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Transplant: Mar 27 🍅 Harvest: Jun 19 – Jul 24
Recommended (50%) ✓ Fits season (80 days to spare)
Transplant: Apr 14 🍅 Harvest: Jul 7 – Aug 11
Safe Start (90%) ✓ Fits season (87 days to spare)
Transplant: May 7 🍅 Harvest: Jul 30 – Sep 3

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
Rutabaga needs ~1,238 GDD — county provides 2,736 GDD Excellent fit

Rutabaga Planting Timeline โ€” Benton County, OR

Rutabaga Planting Calendar

Activity When Date Range
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 21 Aug 21 โ€“ Sep 4
Harvest June 23 Jun 23 โ€“ Jul 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing
September Fall Sowing
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 8a

Growing Season

199 days

Growing Tips for Benton 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 Benton County, OR?

Benton County is in Zone 8a with an average last frost of April 14. Plan your Rutabaga planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Benton County, OR?

Benton County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 30.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Benton County gardeners in Zone 8a 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 Benton County, OR. Local conditions may vary. Last updated: April 2026.