When to Plant Mache in Johnson County, IL
Mache (corn salad) is a cold-hardy salad green with small, rounded, tender leaves and a mild, nutty flavor. It thrives in cool weather and even overwinters in many climates.
Johnson County, Illinois is in USDA Zone 6b. The average last spring frost is April 7 and the first fall frost is October 21, giving you a growing season of approximately 197 days.
At an elevation of 1,006 feet, Johnson County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Mache during the growing season.
Johnson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.2
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 Johnson County
How your county's soil matches Mache's growing requirements.
Soil pH
Your soil pH (5.9–7.2) overlaps with Mache's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Johnson County is excellent for Mache — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Mache will thrive.
How to Plant Mache
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mache
Sow every 4.6 weeks. Last sowing by Aug 22 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Mache
Mache needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mache Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Johnson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mache 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.
Mache Planting Timeline — Johnson County, IL
Mache Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | March 24 | Mar 24 – Apr 14 |
| Harvest | May 19 | May 19 – Jun 23 |
| Fall Sowing | August 12 | Aug 12 – Aug 26 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
197 days in Johnson County
Growing Tips for Mache in Johnson County
Direct sow Mache outdoors after April 07 in Johnson County when soil has warmed and frost danger has passed.
Your generous 197.0-day season in Johnson County allows multiple plantings of Mache. Sow every 20.0 days for continuous harvest.
General growing tips
Direct sow in early spring or late summer for fall and winter harvest. Seeds need light to germinate so press gently into soil surface. Harvest whole rosettes.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Mache in Other Locations
Frequently Asked Questions
When should I plant Mache in Johnson County, IL?
Johnson County is in Zone 6b with an average last frost of April 7. Plan your Mache planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, IL?
Johnson County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 7 and first fall frost is October 21.
Plan Your Garden with Confidence
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