When to Plant Mache in Boulder County, CO
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.
Boulder County, Colorado is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 7,657 feet, Boulder County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Mache during the growing season.
Boulder County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
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 Boulder County
How your county's soil matches Mache's growing requirements.
Soil pH
Your soil pH (6.7–8.0) overlaps with Mache's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Boulder 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 (2.3%). 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 Jul 28 to harvest before frost.
For a dedicated fall crop, sow by Jul 18.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Mache Planting Timeline — Boulder County, CO
Mache Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 9 | Apr 9 – Apr 23 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Direct Sow | April 30 | Apr 30 – May 21 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
| Harvest | June 25 | Jun 25 – Jul 30 |
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 5b
📆 Growing Season
135 days in Boulder County
Growing Tips for Mache in Boulder County
Direct sow Mache outdoors after May 14 in Boulder County when soil has warmed and frost danger has passed.
Boulder County receives only 22" 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
Level Up Your Garden
Mache in Other Locations
Frequently Asked Questions
When should I plant Mache in Boulder County, CO?
Boulder County is in Zone 5b with an average last frost of May 14. Plan your Mache planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boulder County, CO?
Boulder County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 26.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Boulder County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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