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When to Plant Marjoram in Salt Lake County, UT

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.

Salt Lake County, Utah is in USDA Zone 6b. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.

At an elevation of 4,960 feet, Salt Lake County receives approximately 12.2 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Marjoram during the growing season. With low rainfall, drip irrigation is essential for growing Marjoram successfully. Mulch heavily to conserve soil moisture.

Salt Lake County, UT (Zone 6b) Moderate season
157 days
Last Spring Frost May 6
157 growing days
First Fall Frost October 10

Salt Lake County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Sep 13
Recommended (50%) ✓ Fits season (17 days to spare)
Transplant: May 13 🍅 Harvest: Jul 15 – Sep 23
Safe Start (90%) ✓ Fits season (1 days to spare)
Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 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 Salt Lake County

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

Soil pH

Your soil pH (6.7โ€“8.3) overlaps with Marjoram's range (6.5โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Marjoram.

How to Plant Marjoram

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

Succession Planting Marjoram

3
successive plantings in your 157-day season

Sow every 6.9 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.3″/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€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 0.6" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.2" 0" โ„๏ธ Dormant
May 1.3" 1.4" 0" โœ… Rainfall sufficient
Jun 1.3" 1" 0.3" ๐Ÿ’ง Light watering
Jul 1.3" 1.1" 0.2" ๐Ÿ’ง Light watering
Aug 1.3" 1.4" 0" โœ… Rainfall sufficient
Sep 1.3" 0.9" 0.4" ๐Ÿ’ง Light watering
Oct 1.3" 1.2" 0.1" ๐Ÿ’ง Light watering
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Salt Lake 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 ~1,200 GDD — county provides 2,512 GDD Excellent fit

Marjoram Planting Timeline โ€” Salt Lake County, UT

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors May 13 May 13 โ€“ May 27
Harvest July 15 Jul 15 โ€“ Sep 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

157 days in Salt Lake County

Growing Tips for Marjoram in Salt Lake County

Direct sow Marjoram outdoors after May 06 in Salt Lake County when soil has warmed and frost danger has passed.

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 Salt Lake County, UT?

Salt Lake County is in Zone 6b with an average last frost of May 6. Plan your Marjoram planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Salt Lake County, UT?

Salt Lake County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 6 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Salt Lake County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Salt Lake County, UT. Local conditions may vary. Last updated: April 2026.