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When to Plant Marjoram in Starr County, TX

Sweet marjoram is a tender perennial herb with a delicate, sweet oregano-like flavor. It is a cornerstone of Mediterranean cooking and pairs well with meats and vegetables.

Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.

At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98ยฐF, so Marjoram may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marjoram root diseases.

Starr County, TX (Zone 9b) Year-round
316 days
Last Spring Frost February 3
316 growing days
First Fall Frost December 16

Starr County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (186 days to spare)
Transplant: Jan 25 🍅 Harvest: Mar 29 – Jun 7
Recommended (50%) ✓ Fits season (176 days to spare)
Transplant: Feb 10 🍅 Harvest: Apr 14 – Jun 23
Safe Start (90%) ✓ Fits season (157 days to spare)
Transplant: Mar 10 🍅 Harvest: May 12 – 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 Starr County

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

Soil pH

Your soil pH (6.8โ€“7.5) is within Marjoram's preferred range (6.5โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Marjoram.

How to Plant Marjoram

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

Succession Planting Marjoram

6
successive plantings in your 316-day season

Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/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 Marjoram

Marjoram needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Marjoram Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb 1.3" 1.9" 0" โœ… Rainfall sufficient
Mar 1.3" 3.4" 0" โœ… Rainfall sufficient
Apr 1.3" 6.6" 0" โœ… Rainfall sufficient
May 1.3" 8.8" 0" โœ… Rainfall sufficient
Jun 1.3" 7.6" 0" โœ… Rainfall sufficient
Jul 1.3" 7" 0" โœ… Rainfall sufficient
Aug 1.3" 6.4" 0" โœ… Rainfall sufficient
Sep 1.3" 4.9" 0" โœ… Rainfall sufficient
Oct 1.3" 4" 0" โœ… Rainfall sufficient
Nov 1.3" 1.6" 0" โœ… Rainfall sufficient
Dec 1.3" 1.6" 0" โœ… Rainfall sufficient

Water needs are for active growing months only (Febโ€“Dec in Starr County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Marjoram 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.

Marjoram needs ~1,762 GDD — county provides 7,449 GDD Excellent fit

Marjoram Planting Timeline โ€” Starr County, TX

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors February 10 Feb 10 โ€“ Feb 24
Harvest April 14 Apr 14 โ€“ Jun 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March โ€”
April Harvest
May Harvest
June Harvest
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

316 days in Starr County

Growing Tips for Marjoram in Starr County

Direct sow Marjoram outdoors after February 03 in Starr County when soil has warmed and frost danger has passed.

With summer highs reaching 98ยฐF in Starr County, provide afternoon shade for Marjoram and water deeply in the morning.

With 55" of annual rainfall in Starr County, ensure good drainage for Marjoram โ€” excess moisture can promote root rot and fungal diseases.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Harvest stems just as flower buds appear for peak flavor. In cold climates, grow as an annual or bring containers indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Marjoram in Starr County, TX?

Starr County is in Zone 9b with an average last frost of February 3. Plan your Marjoram planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Starr County, TX?

Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Starr County gardeners in Zone 9b 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 Starr County, TX. Local conditions may vary. Last updated: April 2026.