When to Plant Mustard Greens in Petroleum County, MT
Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.
Petroleum County, Montana is in USDA Zone 4a. 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 Mustard Greens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mustard Greens 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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Mustard Greens Planting Timeline — Petroleum County, MT
Mustard Greens 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 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
| Harvest | June 22 | Jun 22 – Aug 24 |
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
Moderate — regular watering
Days to Maturity
30–50 days
Soil pH
6 – 7
USDA Zone
Zone 4a
Growing Season
129 days
Growing Tips for Petroleum County
Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Mustard Greens in Other Locations
Frequently Asked Questions
When should I plant Mustard Greens in Petroleum County, MT?
Petroleum County is in Zone 4a with an average last frost of May 18. Plan your Mustard Greens 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 4a. The average last spring frost is May 18 and first fall frost is September 24.
Plan Your Garden with Confidence
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