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When to Plant Cilantro in Webb County, TX

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.

Webb County, Texas is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 9, giving you a growing season of approximately 303 days.

At an elevation of 3,543 feet, Webb County receives approximately 50.9 inches of rainfall annually with predominantly loam soil. Summer highs average 95ยฐF, 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.

Webb County, TX (Zone 9a) Year-round
303 days
Last Spring Frost February 9
303 growing days
First Fall Frost December 9

Webb County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (219 days to spare)
Start indoors: Dec 22 Transplant: Jan 12 🍅 Harvest: Feb 23 – Apr 27
Recommended (50%) ✓ Fits season (205 days to spare)
Start indoors: Jan 12 Transplant: Feb 2 🍅 Harvest: Mar 16 – May 18
Safe Start (90%) ✓ Fits season (193 days to spare)
Start indoors: Feb 5 Transplant: Feb 26 🍅 Harvest: Apr 9 – Jun 11

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 Webb County

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

Soil pH

Your soil pH (6.6โ€“7.7) is more alkaline than Cilantro prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Webb County is excellent for Cilantro โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). 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 303-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
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Mar 2.2" 2.8" 0" โœ… Rainfall sufficient
Apr 2.2" 5" 0" โœ… Rainfall sufficient
May 2.2" 8.3" 0" โœ… Rainfall sufficient
Jun 2.2" 7.6" 0" โœ… Rainfall sufficient
Jul 2.2" 5.9" 0" โœ… Rainfall sufficient
Aug 2.2" 6.4" 0" โœ… Rainfall sufficient
Sep 2.2" 5.2" 0" โœ… Rainfall sufficient
Oct 2.2" 3.4" 0" โœ… Rainfall sufficient
Nov 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Dec 2.2" 1.5" 0.7" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Webb County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,062 GDD — county provides 6,460 GDD Excellent fit

Cilantro Planting Timeline โ€” Webb County, TX

Cilantro Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 โ€“ Jan 26
Transplant Outdoors February 2 Feb 2 โ€“ Feb 16
Direct Sow January 19 Jan 19 โ€“ Feb 9
Harvest March 16 Mar 16 โ€“ May 18
Fall Sowing October 14 Oct 14 โ€“ Oct 28

Plant 0.5" deep ยท 8" apart ยท 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 โ€”
July โ€”
August โ€”
September โ€”
October Fall Sowing
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

303 days in Webb County

Growing Tips for Cilantro in Webb County

Direct sow Cilantro outdoors after February 09 in Webb County when soil has warmed and frost danger has passed.

Summer highs in Webb County reach 95ยฐF โ€” grow Cilantro as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 304.0-day season in Webb 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 Webb County, TX?

Webb County is in Zone 9a with an average last frost of February 9. Plan your Cilantro planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Webb County, TX?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Webb County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Webb County, TX. Local conditions may vary. Last updated: April 2026.