When to Plant Marjoram in Ross County, OH
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.
Ross County, Ohio is in USDA Zone 6a. The average last spring frost is April 22 and the first fall frost is October 21, giving you a growing season of approximately 182 days.
At an elevation of 1,322 feet, Ross County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Marjoram during the growing season.
Ross County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Ross County
How your county's soil matches Marjoram's growing requirements.
Soil pH
Your soil pH (6.1–6.8) is more acidic than Marjoram prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Ross County is excellent for Marjoram — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Marjoram will thrive.
How to Plant Marjoram
Succession Planting Marjoram
Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 1.3" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Ross County). Supplement amounts are based on average rainfall — 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" — 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.
Marjoram Planting Timeline — Ross County, OH
Marjoram Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Harvest | July 1 | Jul 1 – Sep 9 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
182 days in Ross County
Growing Tips for Marjoram in Ross County
Direct sow Marjoram outdoors after April 22 in Ross 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 →
Marjoram in Other Locations
Frequently Asked Questions
When should I plant Marjoram in Ross County, OH?
Ross County is in Zone 6a with an average last frost of April 22. Plan your Marjoram planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ross County, OH?
Ross County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 22 and first fall frost is October 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Ross County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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