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When to Plant Turnip in Jefferson County, OK

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.

Jefferson County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.

At an elevation of 883 feet, Jefferson County receives approximately 24.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Turnip during the growing season.

Jefferson County, OK (Zone 7b) Long season
228 days
Last Spring Frost March 26
228 growing days
First Fall Frost November 9

Jefferson County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (152 days to spare)
Transplant: Mar 16 🍅 Harvest: Apr 27 – Jun 1
Recommended (50%) ✓ Fits season (151 days to spare)
Transplant: Mar 26 🍅 Harvest: May 7 – Jun 11
Safe Start (90%) ✓ Fits season (146 days to spare)
Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1

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
0.6″/week
Watering frequency 1-2 times/week
Season total 1,106 gal / 100 sq ft
Turnip needs ~912 GDD — county provides 4,161 GDD Excellent fit

Turnip Planting Timeline โ€” Jefferson County, OK

Turnip Planting Calendar

Activity When Date Range
Direct Sow March 12 Mar 12 โ€“ Apr 2
Fall Sowing August 31 Aug 31 โ€“ Sep 14
Harvest April 23 Apr 23 โ€“ May 28

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

Month-by-Month Timeline

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

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

228 days

Growing Tips for Jefferson 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 Jefferson County, OK?

Jefferson County is in Zone 7b with an average last frost of March 26. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, OK?

Jefferson County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 9.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 7b 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 Jefferson County, OK. Local conditions may vary. Last updated: April 2026.