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When to Plant Turnip in Decatur County, TN

Decatur County, Tennessee Zone 7a April

Top priorities for Decatur County, Tennessee gardeners in April

Your Decatur County, Tennessee garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost April 5
Avg. first frost October 27
Soil temp (4") 58°F
Watering Low
Pest pressure Moderate
Daylight 12.9 hrs
A few tasks this April that'll pay off in May
  • 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.

Decatur County, Tennessee is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is October 27, giving you a growing season of approximately 205 days.

At an elevation of 1,168 feet, Decatur County receives approximately 55 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Turnip during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Turnip root diseases.

Decatur County, TN (Zone 7a) Long season
205 days
Last Spring Frost April 5
205 growing days
First Fall Frost October 27

Decatur County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (129 days to spare)
Transplant: Mar 28 🍅 Harvest: May 9 – Jun 13
Recommended (50%) ✓ Fits season (128 days to spare)
Transplant: Apr 5 🍅 Harvest: May 17 – Jun 21
Safe Start (90%) ✓ Fits season (129 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 2 – Jul 7

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 Decatur County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Turnip prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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 205-day season

Sow every 4.6 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 4.2" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 6.5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Decatur 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 ~875 GDD — county provides 3,587 GDD Excellent fit

Turnip Planting Timeline — Decatur County, TN

Turnip Planting Calendar

Activity When Date Range
Direct Sow March 22 Mar 22 – Apr 12
Harvest May 3 May 3 – Jun 7
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April Direct Sow
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 · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

205 days in Decatur County

Growing Tips for Turnip in Decatur County

Direct sow Turnip outdoors after April 05 in Decatur County when soil has warmed and frost danger has passed.

Your generous 205.0-day season in Decatur 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.

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 Decatur County, TN?

Decatur County is in Zone 7a with an average last frost of April 5. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Decatur County, TN?

Decatur County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 27.

🌱

Your Decatur County Garden Planner — Free

A 24-page printable planner built for Decatur County (Zone 7a). 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 Decatur County, TN. Local conditions may vary. Last updated: April 2026.

Sources & credits

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