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When to Plant Shallot in Powell County, MT

Shallots are a gourmet allium prized for their complex, sweet, and mild flavor. Each bulb multiplies into a cluster, making them easy and rewarding to grow.

Powell County, Montana is in USDA Zone 4a. The average last spring frost is June 6 and the first fall frost is September 8, giving you a growing season of approximately 94 days.

At an elevation of 5,514 feet, Powell County receives approximately 22.9 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Shallot to ensure they mature before fall.

Powell County, MT (Zone 4a) Very short season
94 days
Last Spring Frost June 6
94 growing days
First Fall Frost September 8

Powell County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Aug 19 – Oct 7
Recommended (50%) ✗ May not fit
Start indoors: Apr 25 Transplant: Jun 6 🍅 Harvest: Sep 5 – Oct 24
Safe Start (90%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 20 🍅 Harvest: Sep 19 – Nov 7

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Shallot needs ~1,365 GDD — county provides 1,222 GDD May not mature

Shallot Planting Timeline โ€” Powell County, MT

Shallot Planting Calendar

Activity When Date Range
Start Indoors April 25 Apr 25 โ€“ May 9
Transplant Outdoors June 6 Jun 6 โ€“ Jun 20
Direct Sow May 30 May 30 โ€“ Jun 20
Fall Sowing June 16 Jun 16 โ€“ Jun 30
Harvest September 5 Sep 5 โ€“ Oct 24

Plant 1" 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 Direct Sow
June Transplant Outdoors Direct Sow Fall Sowing
July โ€”
August โ€”
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

94 days

Growing Tips for Powell County

Plant sets in fall for spring harvest or early spring for summer harvest. Mulch heavily if overwintering. Harvest when tops brown and dry, then cure for storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Level Up Your Garden

Frequently Asked Questions

When should I plant Shallot in Powell County, MT?

Powell County is in Zone 4a with an average last frost of June 6. Plan your Shallot planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Powell County, MT?

Powell County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is June 6 and first fall frost is September 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Powell 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 Powell County, MT. Local conditions may vary. Last updated: April 2026.