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When to Plant Cilantro in Duval County, TX

Duval County, Texas Zone 9b May

May in Duval County, Texas — your action list

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 13
Avg. first frost December 9
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Bring in the cilantro

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

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Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.

Duval County, Texas is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 9, giving you a growing season of approximately 299 days.

At an elevation of 4,259 feet, Duval County receives approximately 55.2 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Cilantro may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cilantro root diseases.

Duval County, TX (Zone 9b) Year-round
299 days
Last Spring Frost February 13
299 growing days
First Fall Frost December 9

Duval County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (216 days to spare)
Start indoors: Dec 23 Transplant: Jan 13 🍅 Harvest: Feb 24 – Apr 28
Recommended (50%) ✓ Fits season (201 days to spare)
Start indoors: Jan 16 Transplant: Feb 6 🍅 Harvest: Mar 20 – May 22
Safe Start (90%) ✓ Fits season (189 days to spare)
Start indoors: Feb 8 Transplant: Mar 1 🍅 Harvest: Apr 12 – Jun 14

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 Duval County

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

Soil pH

Your soil pH (6.8–7.3) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Cilantro.

How to Plant Cilantro

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Cilantro

9
successive plantings in your 299-day season

Sow every 4.6 weeks. Last sowing by Oct 10 to harvest before frost.

For a dedicated fall crop, sow by Oct 14.

Plant Water Budget

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

Monthly Watering Guide for Cilantro

Cilantro needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Cilantro Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 2.2" 1.7" 0.5" 💧 Light watering
Mar 2.2" 4" 0" ✅ Rainfall sufficient
Apr 2.2" 5.3" 0" ✅ Rainfall sufficient
May 2.2" 8.7" 0" ✅ Rainfall sufficient
Jun 2.2" 8.4" 0" ✅ Rainfall sufficient
Jul 2.2" 6.8" 0" ✅ Rainfall sufficient
Aug 2.2" 6" 0" ✅ Rainfall sufficient
Sep 2.2" 5.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.6" 0" ✅ Rainfall sufficient
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 2.2" 1.6" 0.6" 💧 Light watering

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

Cilantro 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.

Cilantro needs ~1,325 GDD — county provides 7,950 GDD Excellent fit

Cilantro Planting Timeline — Duval County, TX

Cilantro Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors February 6 Feb 6 – Feb 20
Direct Sow January 23 Jan 23 – Feb 13
Harvest March 20 Mar 20 – May 22
Fall Sowing October 14 Oct 14 – Oct 28

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

299 days in Duval County

Growing Tips for Cilantro in Duval County

Direct sow Cilantro outdoors after February 13 in Duval County when soil has warmed and frost danger has passed.

Summer highs in Duval County reach 102°F — grow Cilantro as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 300.0-day season in Duval County allows multiple plantings of Cilantro. Sow every 20.0 days for continuous harvest.

Common pests for Cilantro in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

With 55" of annual rainfall in Duval County, ensure good drainage for Cilantro — excess moisture can promote root rot and fungal diseases.

General growing tips

Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cilantro in Duval County, TX?

Duval County is in Zone 9b with an average last frost of February 13. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Duval County, TX?

Duval County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 9.

🌱

Your Duval County Garden Planner — Free

A 24-page printable planner built for Duval County (Zone 9b). 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 Duval 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.