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When to Plant Mustard Greens in Comal County, TX

Comal County, Texas Zone 9a May

What to do in May

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

Avg. last frost March 6
Avg. first frost November 22
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: mustard greens

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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  • First harvests: mustard greens

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Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Comal County, Texas is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 22, giving you a growing season of approximately 261 days.

At an elevation of 1,346 feet, Comal County receives approximately 58.6 inches of rainfall annually with predominantly clay soil. Summer highs average 91°F, providing good warmth for Mustard Greens during the growing season. Clay soil retains moisture well for Mustard Greens, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mustard Greens root diseases.

Comal County, TX (Zone 9a) Long season
261 days
Last Spring Frost March 6
261 growing days
First Fall Frost November 22
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Comal County Soil Profile

Soil Type

Clay

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (165 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Mar 31 – Jun 2
Recommended (50%) ✓ Fits season (163 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: Apr 10 – Jun 12
Safe Start (90%) ✓ Fits season (155 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 7 – Jul 9

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 Comal County

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Mustard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (47% clay) in Comal County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Drainage

Drainage is adequate for Mustard Greens.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Mustard Greens.

How to Plant Mustard Greens

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Mustard Greens

10
successive plantings in your 261-day season

Sow every 3.4 weeks. Last sowing by Oct 03 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
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Mustard Greens

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

Month Mustard Greens Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 3" 3.8" 0" ✅ Rainfall sufficient
Apr 3" 6.6" 0" ✅ Rainfall sufficient
May 3" 9.4" 0" ✅ Rainfall sufficient
Jun 3" 9.9" 0" ✅ Rainfall sufficient
Jul 3" 6.6" 0" ✅ Rainfall sufficient
Aug 3" 6.4" 0" ✅ Rainfall sufficient
Sep 3" 4.9" 0" ✅ Rainfall sufficient
Oct 3" 3.9" 0" ✅ Rainfall sufficient
Nov 3" 2" 1" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

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

Mustard Greens 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.

Mustard Greens needs ~730 GDD — county provides 4,763 GDD Excellent fit

Mustard Greens Planting Timeline — Comal County, TX

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow February 13 Feb 13 – Mar 6
Harvest April 10 Apr 10 – Jun 12
Fall Sowing September 27 Sep 27 – Oct 11

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

261 days in Comal County

Growing Tips for Mustard Greens in Comal County

Direct sow Mustard Greens outdoors after March 06 in Comal County when soil has warmed and frost danger has passed.

With Comal County's clay soil (47% clay), work in 3-4 inches of compost before planting Mustard Greens. Avoid tilling when soil is wet to prevent compaction.

Your generous 261.0-day season in Comal County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.

Common pests for Mustard Greens 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 fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Comal County, TX?

Comal County is in Zone 9a with an average last frost of March 6. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Comal County, TX?

Comal County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 22.

🌱

Your Comal County Garden Planner — Free

A 24-page printable planner built for Comal 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 Comal 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.