When to Plant Mache in Washington County, ID
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.
Washington County, Idaho is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.
At an elevation of 4,048 feet, Washington County receives approximately 17.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Mache during the growing season. With low rainfall, drip irrigation is essential for growing Mache successfully. Mulch heavily to conserve soil moisture.
Washington County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 Washington County
How your county's soil matches Mache's growing requirements.
Soil pH
Your soil pH (6.2–7.8) overlaps with Mache's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Washington County is excellent for Mache — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Mache.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Mache.
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 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 23.
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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jul | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Aug | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Oct | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Washington 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 — Washington County, ID
Mache Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | June 20 | Jun 20 – Jul 25 |
| Fall Sowing | July 23 | Jul 23 – Aug 6 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
145 days in Washington County
Growing Tips for Mache in Washington County
Direct sow Mache outdoors after May 09 in Washington County when soil has warmed and frost danger has passed.
Washington County receives only 18" of rain annually. Mache needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Washington County, ID?
Washington County is in Zone 6a with an average last frost of May 9. Plan your Mache planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, ID?
Washington County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 1.
Plan Your Garden with Confidence
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