When to Plant Mache in Petroleum County, MT
Your May game plan for Petroleum County, Montana
Here's what deserves your attention in Petroleum County, Montana this month. Everything below is tailored to Zone 4b and timed around your local frost dates.
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Move mache from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Direct-sow mache
Your soil is 30°F — warm enough for these to germinate without babying.
A few tasks this May that'll pay off in June
- Starting indoors: mache
- First harvests: mache
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.
Petroleum County, Montana is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is September 24, giving you a growing season of approximately 129 days.
At an elevation of 8,358 feet, Petroleum County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Mache to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mache successfully. Mulch heavily to conserve soil moisture.
Petroleum County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.2
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 Petroleum County
How your county's soil matches Mache's growing requirements.
Soil pH
Your soil pH (6.8–8.2) overlaps with Mache's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Petroleum 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 (2.7%). Annual compost additions will help Mache.
How to Plant Mache
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Mache
Sow every 4.6 weeks. Last sowing by Jul 26 to harvest before frost.
For a dedicated fall crop, sow by Jul 02.
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 | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Aug | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Sep | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Petroleum 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 — Petroleum County, MT
Mache Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | June 29 | Jun 29 – Aug 3 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| 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 4b
📆 Growing Season
129 days in Petroleum County
Growing Tips for Mache in Petroleum County
Direct sow Mache outdoors after May 18 in Petroleum County when soil has warmed and frost danger has passed.
Petroleum County receives only 14" 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 Petroleum County, MT?
Petroleum County is in Zone 4b with an average last frost of May 18. Plan your Mache planting based on this frost date — see the calendar above for exact timing.
What planting zone is Petroleum County, MT?
Petroleum County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is September 24.
Your Petroleum County Garden Planner — Free
A 24-page printable planner built for Petroleum County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.