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When to Plant Rutabaga in Williamson County, TX

Williamson County, Texas Zone 9a May

What to do in May

A quick May briefing for Williamson County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 5
Avg. first frost November 22
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Basket week: rutabaga

    If you can't use it all right away, check the food-preservation section of your planner.

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

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Rutabagas are a cross between turnips and cabbage, producing large yellow-fleshed roots with a sweet, mild flavor. They are excellent mashed, roasted, or in stews.

Williamson County, Texas is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 22, giving you a growing season of approximately 262 days.

At an elevation of 1,023 feet, Williamson County receives approximately 53.3 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Rutabaga during the growing season. Clay soil retains moisture well for Rutabaga, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rutabaga root diseases.

Williamson County, TX (Zone 9a) Long season
262 days
Last Spring Frost March 5
262 growing days
First Fall Frost November 22
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Williamson County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (145 days to spare)
Transplant: Feb 21 🍅 Harvest: May 16 – Jun 20
Recommended (50%) ✓ Fits season (143 days to spare)
Transplant: Mar 5 🍅 Harvest: May 28 – Jul 2
Safe Start (90%) ✓ Fits season (131 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 29 – Aug 3

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 Williamson County

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

Soil pH

Your soil pH (7.1–7.8) overlaps with Rutabaga's range (6.0–7.5), though not a perfect match.

Soil Texture

Your soil has 46% clay, which can cause forked or stunted roots for Rutabaga. Use raised beds with loose, sandy mix for best results.

Drainage

Drainage is adequate for Rutabaga.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Rutabaga.

How to Plant Rutabaga

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Rutabaga

3
successive plantings in your 262-day season

Sow every 9.1 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Sep 27.

Plant Water Budget

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

Monthly Watering Guide for Rutabaga

Rutabaga needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Rutabaga Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3" 3.4" 0" ✅ Rainfall sufficient
Apr 3" 6.5" 0" ✅ Rainfall sufficient
May 3" 7.7" 0" ✅ Rainfall sufficient
Jun 3" 7.6" 0" ✅ Rainfall sufficient
Jul 3" 6.6" 0" ✅ Rainfall sufficient
Aug 3" 6.1" 0" ✅ Rainfall sufficient
Sep 3" 5.4" 0" ✅ Rainfall sufficient
Oct 3" 3.7" 0" ✅ Rainfall sufficient
Nov 3" 1.7" 1.3" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Williamson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Rutabaga 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.

Rutabaga needs ~1,845 GDD — county provides 5,371 GDD Excellent fit

Rutabaga Planting Timeline — Williamson County, TX

Rutabaga Planting Calendar

Activity When Date Range
Direct Sow February 12 Feb 12 – Mar 5
Harvest May 7 May 7 – Jun 11
Fall Sowing September 27 Sep 27 – Oct 11

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

262 days in Williamson County

Growing Tips for Rutabaga in Williamson County

Direct sow Rutabaga outdoors after March 05 in Williamson County when soil has warmed and frost danger has passed.

With Williamson County's clay soil (46% clay), work in 3-4 inches of compost before planting Rutabaga. Avoid tilling when soil is wet to prevent compaction.

Common pests for Rutabaga 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 summer for fall harvest. Thin seedlings to 6-8 inches apart. Flavor improves significantly after a few light frosts.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rutabaga in Williamson County, TX?

Williamson County is in Zone 9a with an average last frost of March 5. Plan your Rutabaga planting based on this frost date — see the calendar above for exact timing.

What planting zone is Williamson County, TX?

Williamson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 22.

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Your Williamson County Garden Planner — Free

A 24-page printable planner built for Williamson 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 Williamson 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.