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When to Plant Turnip in Harper 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.

Harper County, Oklahoma is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.

At an elevation of 861 feet, Harper County receives approximately 21.5 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Turnip during the growing season.

Harper County, OK (Zone 6b) Moderate season
186 days
Last Spring Frost April 15
186 growing days
First Fall Frost October 18

Harper County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Transplant: Apr 13 🍅 Harvest: May 25 – Jun 29
Recommended (50%) ✓ Fits season (109 days to spare)
Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1
Safe Start (90%) ✓ Fits season (108 days to spare)
Transplant: May 1 🍅 Harvest: Jun 12 – Jul 17

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 1,022 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Turnip needs ~838 GDD — county provides 3,115 GDD Excellent fit

Turnip Planting Timeline โ€” Harper County, OK

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 1 Apr 1 โ€“ Apr 22
Fall Sowing August 9 Aug 9 โ€“ Aug 23
Harvest May 13 May 13 โ€“ Jun 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Harvest
June Harvest
July โ€”
August Fall Sowing
September โ€”
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 6b

Growing Season

186 days

Growing Tips for Harper 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 Harper County, OK?

Harper County is in Zone 6b with an average last frost of April 15. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harper County, OK?

Harper County, Oklahoma is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harper 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 Harper County, OK. Local conditions may vary. Last updated: April 2026.