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When to Plant Turnip in Seminole County, OK

Seminole County, Oklahoma Zone 7b May

May in the garden — Seminole County, Oklahoma

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Seminole County, Oklahoma.

Avg. last frost March 31
Avg. first frost November 6
Soil temp (4") 69°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Start harvesting turnip

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Coming up in June — start thinking about
  • First harvests: turnip

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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.

Seminole County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 6, giving you a growing season of approximately 220 days.

At an elevation of 961 feet, Seminole County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Turnip during the growing season.

Seminole County, OK (Zone 7b) Long season
220 days
Last Spring Frost March 31
220 growing days
First Fall Frost November 6

Seminole 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 (141 days to spare)
Transplant: Mar 24 🍅 Harvest: May 5 – Jun 9
Recommended (50%) ✓ Fits season (143 days to spare)
Transplant: Mar 31 🍅 Harvest: May 12 – Jun 16
Safe Start (90%) ✓ Fits season (145 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.

Soil Compatibility in Seminole County

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

Soil pH

Your soil pH (6.7–7.5) is more alkaline than Turnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Seminole County is excellent for Turnip — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). 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

6
successive plantings in your 220-day season

Sow every 4.6 weeks. Last sowing by Sep 07 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,421 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 4.3" 1.4" 2.9" 🚿 Regular watering
Apr 4.3" 2.1" 2.2" 🚿 Regular watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 2.4" 1.9" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 4.3" 0.8" 3.5" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Seminole County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,025 GDD — county provides 4,510 GDD Excellent fit

Turnip Planting Timeline — Seminole County, OK

Turnip Planting Calendar

Activity When Date Range
Direct Sow March 17 Mar 17 – Apr 7
Harvest April 28 Apr 28 – Jun 2
Fall Sowing August 28 Aug 28 – Sep 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

220 days in Seminole County

Growing Tips for Turnip in Seminole County

Direct sow Turnip outdoors after March 31 in Seminole County when soil has warmed and frost danger has passed.

Your generous 220.0-day season in Seminole 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.

Seminole County receives only 21" of rain annually. Turnip needs consistent moisture — 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 Seminole County, OK?

Seminole County is in Zone 7b with an average last frost of March 31. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Seminole County, OK?

Seminole County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 6.

🌱

Your Seminole County Garden Planner — Free

A 24-page printable planner built for Seminole County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Seminole County, OK. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.