When to Plant Marjoram in Mason County, IL
What to do in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
Coming up in June — start thinking about
- First harvests: marjoram
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.
Mason County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 14, giving you a growing season of approximately 182 days.
At an elevation of 768 feet, Mason County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Marjoram during the growing season.
Mason County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.9
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 Mason County
How your county's soil matches Marjoram's growing requirements.
Soil pH
Your soil pH (6.1–6.9) overlaps with Marjoram's range (6.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Mason County is excellent for Marjoram — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Marjoram will thrive.
How to Plant Marjoram
Succession Planting Marjoram
Sow every 6.9 weeks. Last sowing by Jul 16 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | 1.3" | 3" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Mason 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 — Mason County, IL
Marjoram Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Harvest | June 24 | Jun 24 – Sep 2 |
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 | Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
182 days in Mason County
Growing Tips for Marjoram in Mason County
Direct sow Marjoram outdoors after April 15 in Mason 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 Mason County, IL?
Mason County is in Zone 6a with an average last frost of April 15. Plan your Marjoram planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mason County, IL?
Mason County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 14.
Your Mason County Garden Planner — Free
A 24-page printable planner built for Mason County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.