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When to Plant Mustard Greens in Madison 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.

Madison County, Montana is in USDA Zone 4a. The average last spring frost is June 11 and the first fall frost is September 13, giving you a growing season of approximately 94 days.

At an elevation of 6,394 feet, Madison County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Mustard Greens to ensure they mature before fall.

Madison County, MT (Zone 4a) Very short season
94 days
Last Spring Frost June 11
94 growing days
First Fall Frost September 13

Madison County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 22 Transplant: Jun 3 🍅 Harvest: Jul 8 – Sep 9
Recommended (50%) ✗ May not fit
Start indoors: Apr 30 Transplant: Jun 11 🍅 Harvest: Jul 16 – Sep 17
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: May 11 Transplant: Jun 22 🍅 Harvest: Jul 27 – Sep 28

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

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 377 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Mustard Greens needs ~400 GDD — county provides 940 GDD Excellent fit

Mustard Greens Planting Timeline โ€” Madison County, MT

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors April 30 Apr 30 โ€“ May 14
Transplant Outdoors June 11 Jun 11 โ€“ Jun 25
Direct Sow June 4 Jun 4 โ€“ Jun 25
Fall Sowing June 21 Jun 21 โ€“ Jul 5
Harvest July 16 Jul 16 โ€“ Sep 17

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Start Indoors
June Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

94 days

Growing Tips for Madison 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

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Mustard Greens in Madison County, MT?

Madison County is in Zone 4a with an average last frost of June 11. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Madison County, MT?

Madison County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is June 11 and first fall frost is September 13.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Madison County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Madison County, MT. Local conditions may vary. Last updated: April 2026.