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When to Plant Cilantro in Tom Green County, TX

Tom Green County, Texas Zone 8a May

May in Tom Green County, Texas — your action list

Each item below is timed to Tom Green County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 25
Avg. first frost November 12
Soil temp (4") 58°F
Watering High
Pest pressure Moderate
Daylight 13.6 hrs
  1. Basket week: cilantro

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this May that'll pay off in June
  • 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.

Tom Green County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 4,366 feet, Tom Green County receives approximately 52.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Cilantro may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Cilantro will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cilantro root diseases.

Tom Green County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12

Tom Green County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (138 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 16 – Jun 18
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Feb 18 Transplant: Mar 18 🍅 Harvest: Apr 29 – Jul 1
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: May 19 – Jul 21

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 Tom Green County

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

Soil pH

Your soil pH (7.2–8.3) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Tom Green County warms quickly in spring but drains fast. Cilantro will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Cilantro.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Cilantro.

How to Plant Cilantro

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cilantro

7
successive plantings in your 232-day season

Sow every 4.6 weeks. Last sowing by Sep 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

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
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 3" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 2.2" 3.1" 0" ✅ Rainfall sufficient
Apr 2.2" 1.5" 0.7" 💧 Light watering
May 2.2" 1.3" 0.9" 💧 Light watering
Jun 2.2" 1.9" 0.3" 💧 Light watering
Jul 2.2" 9.5" 0" ✅ Rainfall sufficient
Aug 2.2" 10.3" 0" ✅ Rainfall sufficient
Sep 2.2" 7.4" 0" ✅ Rainfall sufficient
Oct 2.2" 4.8" 0" ✅ Rainfall sufficient
Nov 2.2" 2.7" 0" ✅ Rainfall sufficient
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tom Green 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 6,148 GDD Excellent fit

Cilantro Planting Timeline — Tom Green County, TX

Cilantro Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 11 Mar 11 – Apr 1
Harvest April 29 Apr 29 – Jul 1
Fall Sowing September 3 Sep 3 – Sep 17

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow Harvest
May Harvest
June Harvest
July Harvest
August
September Fall Sowing
October
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 8a

📆 Growing Season

232 days in Tom Green County

Growing Tips for Cilantro in Tom Green County

Direct sow Cilantro outdoors after March 25 in Tom Green County when soil has warmed and frost danger has passed.

Sandy soil in Tom Green County dries quickly — mulch Cilantro with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

Your generous 232.0-day season in Tom Green 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.

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 Tom Green County, TX?

Tom Green County is in Zone 8a with an average last frost of March 25. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tom Green County, TX?

Tom Green County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

🌱

Your Tom Green County Garden Planner — Free

A 24-page printable planner built for Tom Green County (Zone 8a). 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 Tom Green 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.