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When to Plant Cilantro in Hays County, TX

Hays County, Texas Zone 9a May

May to-do list for Hays County, Texas

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 6
Avg. first frost November 22
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest cilantro as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

June will be here before you know it — start on
  • First harvests: cilantro

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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.

Hays 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 3,119 feet, Hays County receives approximately 61.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Cilantro during the growing season. Clay soil retains moisture well for Cilantro, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cilantro root diseases.

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

Hays County Soil Profile

Soil Type

Clay

Soil pH

7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (165 days to spare)
Start indoors: Jan 27 Transplant: Feb 17 🍅 Harvest: Mar 31 – Jun 2
Recommended (50%) ✓ Fits season (163 days to spare)
Start indoors: Feb 6 Transplant: Feb 27 🍅 Harvest: Apr 10 – Jun 12
Safe Start (90%) ✓ Fits season (155 days to spare)
Start indoors: Mar 5 Transplant: Mar 26 🍅 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 Hays County

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

Soil pH

Your soil pH (7.0–8.0) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (45% clay) in Hays County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.8%). 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

7
successive plantings in your 261-day season

Sow every 4.6 weeks. Last sowing by Sep 23 to harvest before frost.

For a dedicated fall crop, sow by Sep 27.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 2.3" 0" ❄️ Dormant
Mar 2.2" 3.5" 0" ✅ Rainfall sufficient
Apr 2.2" 6.5" 0" ✅ Rainfall sufficient
May 2.2" 9.5" 0" ✅ Rainfall sufficient
Jun 2.2" 9.8" 0" ✅ Rainfall sufficient
Jul 2.2" 7" 0" ✅ Rainfall sufficient
Aug 2.2" 8.1" 0" ✅ Rainfall sufficient
Sep 2.2" 5.1" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 2.3" 0" ✅ Rainfall sufficient
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Hays 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 ~875 GDD — county provides 4,567 GDD Excellent fit

Cilantro Planting Timeline — Hays County, TX

Cilantro Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors February 27 Feb 27 – Mar 13
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 · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June Harvest
July
August
September Fall Sowing
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 9a

📆 Growing Season

261 days in Hays County

Growing Tips for Cilantro in Hays County

Direct sow Cilantro outdoors after March 06 in Hays County when soil has warmed and frost danger has passed.

With Hays County's clay soil (45% clay), work in 3-4 inches of compost before planting Cilantro. Avoid tilling when soil is wet to prevent compaction.

Your generous 261.0-day season in Hays 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 62" of annual rainfall in Hays 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 Hays County, TX?

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

What planting zone is Hays County, TX?

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

🌱

Your Hays County Garden Planner — Free

A 24-page printable planner built for Hays 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 Hays 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.