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When to Plant Parsley in Castro County, TX

Castro County, Texas Zone 7a May

Your May gardening checklist

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

Avg. last frost April 14
Avg. first frost October 24
Soil temp (4") 60°F
Watering Critical
Pest pressure Moderate
Daylight 13.8 hrs
  1. Indoor seed-starting week for parsley

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

A few tasks this May that'll pay off in June
  • First harvests: parsley

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Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

Castro County, Texas is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 3,838 feet, Castro County receives approximately 47.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Parsley may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Parsley will need more frequent watering and organic matter to retain nutrients.

Castro County, TX (Zone 7a) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24
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Castro County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Mar 3 Transplant: Mar 31 🍅 Harvest: Jun 2 – Aug 4
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 9 – Aug 11
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Mar 27 Transplant: Apr 24 🍅 Harvest: Jun 26 – Aug 28

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 Castro County

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

Soil pH

Your soil pH (7.5–8.1) is more alkaline than Parsley prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.0%). Add 2-3 inches of compost before planting Parsley.

How to Plant Parsley

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 Parsley

3
successive plantings in your 193-day season

Sow every 6.9 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Plant Water Budget

Plant needs
0.6″/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 Parsley

Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Parsley Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.6" 1.7" 0.9" 💧 Light watering
May 2.6" 1.2" 1.4" 🚿 Regular watering
Jun 2.6" 1.5" 1.1" 💧 Light watering
Jul 2.6" 8" 0" ✅ Rainfall sufficient
Aug 2.6" 8.9" 0" ✅ Rainfall sufficient
Sep 2.6" 6.8" 0" ✅ Rainfall sufficient
Oct 2.6" 4.9" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

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

Parsley 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.

Parsley needs ~1,488 GDD — county provides 4,101 GDD Excellent fit

Parsley Planting Timeline — Castro County, TX

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 31 Mar 31 – Apr 21
Harvest June 9 Jun 9 – Aug 11
Fall Sowing August 15 Aug 15 – Aug 29

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

193 days in Castro County

Growing Tips for Parsley in Castro County

Direct sow Parsley outdoors after April 14 in Castro County when soil has warmed and frost danger has passed.

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

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

General growing tips

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsley in Castro County, TX?

Castro County is in Zone 7a with an average last frost of April 14. Plan your Parsley planting based on this frost date — see the calendar above for exact timing.

What planting zone is Castro County, TX?

Castro County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.

🌱

Your Castro County Garden Planner — Free

A 24-page printable planner built for Castro County (Zone 7a). 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 Castro 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.