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When to Plant Parsley in Harris County, TX

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.

Harris County, Texas is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.

At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102ยฐF, so Parsley may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Parsley will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Parsley root diseases.

Harris County, TX (Zone 9a) Year-round
293 days
Last Spring Frost February 14
293 growing days
First Fall Frost December 4

Harris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (174 days to spare)
Start indoors: Jan 9 Transplant: Jan 30 🍅 Harvest: Apr 3 – Jun 5
Recommended (50%) ✓ Fits season (174 days to spare)
Start indoors: Jan 17 Transplant: Feb 7 🍅 Harvest: Apr 11 – Jun 13
Safe Start (90%) ✓ Fits season (170 days to spare)
Start indoors: Feb 8 Transplant: Mar 1 🍅 Harvest: May 3 – Jul 5

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 Harris County

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

Soil pH

Your soil pH (5.3โ€“6.5) is more acidic than Parsley prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Harris 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 moderate (2.2%). Annual compost additions will help Parsley.

How to Plant Parsley

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 Parsley

5
successive plantings in your 293-day season

Sow every 6.9 weeks. Last sowing by Sep 15 to harvest before frost.

For a dedicated fall crop, sow by Oct 09.

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

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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb 2.6" 2.7" 0" โœ… Rainfall sufficient
Mar 2.6" 3.8" 0" โœ… Rainfall sufficient
Apr 2.6" 7.4" 0" โœ… Rainfall sufficient
May 2.6" 10.1" 0" โœ… Rainfall sufficient
Jun 2.6" 10" 0" โœ… Rainfall sufficient
Jul 2.6" 9.6" 0" โœ… Rainfall sufficient
Aug 2.6" 8.5" 0" โœ… Rainfall sufficient
Sep 2.6" 6.3" 0" โœ… Rainfall sufficient
Oct 2.6" 3.9" 0" โœ… Rainfall sufficient
Nov 2.6" 2.2" 0.4" ๐Ÿ’ง Light watering
Dec 2.6" 1.6" 1" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Harris County). Supplement amounts are based on average rainfall โ€” 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" 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.

Parsley needs ~1,855 GDD — county provides 7,791 GDD Excellent fit

Parsley Planting Timeline โ€” Harris County, TX

Parsley Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 โ€“ Jan 31
Transplant Outdoors February 7 Feb 7 โ€“ Feb 21
Direct Sow January 24 Jan 24 โ€“ Feb 14
Harvest April 11 Apr 11 โ€“ Jun 13
Fall Sowing October 9 Oct 9 โ€“ Oct 23

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 โ€”
April Harvest
May Harvest
June Harvest
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

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

293 days in Harris County

Growing Tips for Parsley in Harris County

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

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

With summer highs reaching 102ยฐF in Harris County, provide afternoon shade for Parsley and water deeply in the morning.

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 Harris County, TX?

Harris County is in Zone 9a with an average last frost of February 14. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harris County, TX?

Harris County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harris 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 Harris County, TX. Local conditions may vary. Last updated: April 2026.