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When to Plant Marjoram in Collin 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.

Collin County, Texas is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94ยฐF, providing good warmth for Marjoram during the growing season. Clay soil retains moisture well for Marjoram, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marjoram root diseases.

Collin County, TX (Zone 8a) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Collin County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (114 days to spare)
Transplant: Mar 9 🍅 Harvest: May 11 – Jul 20
Recommended (50%) ✓ Fits season (115 days to spare)
Transplant: Mar 17 🍅 Harvest: May 19 – Jul 28
Safe Start (90%) ✓ Fits season (100 days to spare)
Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 29

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 Collin County

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

Soil pH

Your soil pH (7.3โ€“7.8) is more alkaline than Marjoram prefers (6.5โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (43% clay) in Collin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Marjoram.

How to Plant Marjoram

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

Succession Planting Marjoram

5
successive plantings in your 255-day season

Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
1.1″/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€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 2.2" 0" โ„๏ธ Dormant
Mar 1.3" 4.3" 0" โœ… Rainfall sufficient
Apr 1.3" 6.9" 0" โœ… Rainfall sufficient
May 1.3" 10.2" 0" โœ… Rainfall sufficient
Jun 1.3" 9.9" 0" โœ… Rainfall sufficient
Jul 1.3" 7.3" 0" โœ… Rainfall sufficient
Aug 1.3" 8.4" 0" โœ… Rainfall sufficient
Sep 1.3" 6.5" 0" โœ… Rainfall sufficient
Oct 1.3" 3.9" 0" โœ… Rainfall sufficient
Nov 1.3" 2.2" 0" โœ… Rainfall sufficient
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Collin 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 ~1,538 GDD — county provides 5,227 GDD Excellent fit

Marjoram Planting Timeline โ€” Collin County, TX

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors March 17 Mar 17 โ€“ Mar 31
Harvest May 19 May 19 โ€“ Jul 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
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: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

255 days in Collin County

Growing Tips for Marjoram in Collin County

Direct sow Marjoram outdoors after March 10 in Collin County when soil has warmed and frost danger has passed.

With Collin County's clay soil (43% clay), work in 3-4 inches of compost before planting Marjoram. Avoid tilling when soil is wet to prevent compaction.

With 65" of annual rainfall in Collin 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 Collin County, TX?

Collin County is in Zone 8a with an average last frost of March 10. Plan your Marjoram planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Collin County, TX?

Collin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Collin County gardeners in Zone 8a 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 Collin County, TX. Local conditions may vary. Last updated: April 2026.