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When to Plant Turnip in Karnes County, TX

Karnes County, Texas Zone 9a May

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Avg. last frost February 26
Avg. first frost November 30
Soil temp (4") 59°F
Watering Low
Pest pressure High
Daylight 13.4 hrs

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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.

Karnes County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 30, giving you a growing season of approximately 277 days.

At an elevation of 4,532 feet, Karnes County receives approximately 67.2 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Turnip may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Turnip root diseases.

Karnes County, TX (Zone 9a) Year-round
277 days
Last Spring Frost February 26
277 growing days
First Fall Frost November 30
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Karnes County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (204 days to spare)
Transplant: Feb 14 🍅 Harvest: Mar 28 – May 2
Recommended (50%) ✓ Fits season (200 days to spare)
Transplant: Feb 26 🍅 Harvest: Apr 9 – May 14
Safe Start (90%) ✓ Fits season (196 days to spare)
Transplant: Mar 23 🍅 Harvest: May 4 – Jun 8

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 Karnes County

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

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Turnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Turnip.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Turnip.

How to Plant Turnip

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

8
successive plantings in your 277-day season

Sow every 4.6 weeks. Last sowing by Oct 01 to harvest before frost.

For a dedicated fall crop, sow by Oct 05.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 705 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 1.6" 0" ❄️ Dormant
Feb 4.3" 2.6" 1.7" 💧 Light watering
Mar 4.3" 4.6" 0" ✅ Rainfall sufficient
Apr 4.3" 6.3" 0" ✅ Rainfall sufficient
May 4.3" 8.6" 0" ✅ Rainfall sufficient
Jun 4.3" 11.7" 0" ✅ Rainfall sufficient
Jul 4.3" 9.1" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.7" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Karnes 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 ~1,062 GDD — county provides 5,907 GDD Excellent fit

Turnip Planting Timeline — Karnes County, TX

Turnip Planting Calendar

Activity When Date Range
Direct Sow February 5 Feb 5 – Feb 26
Harvest March 19 Mar 19 – Apr 23
Fall Sowing October 5 Oct 5 – Oct 19

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Karnes County

Growing Tips for Turnip in Karnes County

Direct sow Turnip outdoors after February 26 in Karnes County when soil has warmed and frost danger has passed.

Your generous 278.0-day season in Karnes 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 Karnes County, TX?

Karnes County is in Zone 9a with an average last frost of February 26. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Karnes County, TX?

Karnes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 30.

🌱

Your Karnes County Garden Planner — Free

A 24-page printable planner built for Karnes County (Zone 9a). 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 Karnes County, TX. 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.