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When to Plant Turnip in Marshall 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.

Marshall County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.

At an elevation of 520 feet, Marshall County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Turnip during the growing season.

Marshall County, OK (Zone 7b) Long season
233 days
Last Spring Frost March 24
233 growing days
First Fall Frost November 12

Marshall County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (160 days to spare)
Transplant: Mar 11 🍅 Harvest: Apr 22 – May 27
Recommended (50%) ✓ Fits season (156 days to spare)
Transplant: Mar 24 🍅 Harvest: May 5 – Jun 9
Safe Start (90%) ✓ Fits season (153 days to spare)
Transplant: Apr 14 🍅 Harvest: May 26 – Jun 30

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.

Soil Compatibility in Marshall County

How your county's soil matches Turnip's growing requirements.

Soil pH

Your soil pH (6.2โ€“7.8) overlaps with Turnip's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Marshall County is excellent for Turnip โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Turnip.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Turnip.

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

7
successive plantings in your 233-day season

Sow every 4.6 weeks. Last sowing by Sep 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,172 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Turnip

Turnip needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Turnip Needs Rainfall You Supplement Action
Jan โ€” 0.5" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Apr 4.3" 2.3" 2" ๐Ÿ’ง Light watering
May 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jun 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jul 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Aug 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Nov 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Marshall County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Turnip Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Turnip needs ~950 GDD — county provides 4,427 GDD Excellent fit

Turnip Planting Timeline โ€” Marshall County, OK

Turnip Planting Calendar

Activity When Date Range
Direct Sow March 10 Mar 10 โ€“ Mar 31
Harvest April 21 Apr 21 โ€“ May 26
Fall Sowing September 3 Sep 3 โ€“ Sep 17

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

233 days in Marshall County

Growing Tips for Turnip in Marshall County

Direct sow Turnip outdoors after March 24 in Marshall County when soil has warmed and frost danger has passed.

Your generous 233.0-day season in Marshall County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.

Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Marshall County receives only 24" of rain annually. Turnip needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in Marshall County, OK?

Marshall County is in Zone 7b with an average last frost of March 24. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marshall County, OK?

Marshall County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 24 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marshall County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Marshall County, OK. Local conditions may vary. Last updated: April 2026.