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When to Plant Turnip in Napa County, CA

Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Napa County, California is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Turnip during the growing season.

Napa County, CA (Zone 9a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Napa County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (208 days to spare)
Transplant: Feb 10 🍅 Harvest: Mar 24 – Apr 28
Recommended (50%) ✓ Fits season (196 days to spare)
Transplant: Feb 26 🍅 Harvest: Apr 9 – May 14
Safe Start (90%) ✓ Fits season (182 days to spare)
Transplant: Apr 2 🍅 Harvest: May 14 – Jun 18

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
0.9″/week
Watering frequency 2-3 times/week
Season total 2,234 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Turnip needs ~800 GDD — county provides 4,384 GDD Excellent fit

Turnip Planting Timeline โ€” Napa County, CA

Turnip Planting Calendar

Activity When Date Range
Direct Sow February 5 Feb 5 โ€“ Feb 26
Fall Sowing October 1 Oct 1 โ€“ Oct 15
Harvest March 19 Mar 19 โ€“ Apr 23

Plant 0.5" deep ยท 4" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

273 days

Growing Tips for Napa County

Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Turnip in Napa County, CA?

Napa County is in Zone 9a with an average last frost of February 26. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Napa County, CA?

Napa County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Napa County gardeners in Zone 9a 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 Napa County, CA. Local conditions may vary. Last updated: April 2026.