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When to Plant Shallot in Grand County, CO

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.

Grand County, Colorado is in USDA Zone 4a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Shallot to ensure they mature before fall.

Grand County, CO (Zone 4a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19

Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Aug 12 – Sep 30
Recommended (50%) ✗ May not fit
Start indoors: Apr 16 Transplant: May 28 🍅 Harvest: Aug 27 – Oct 15
Safe Start (90%) ✗ May not fit
Start indoors: May 7 Transplant: Jun 18 🍅 Harvest: Sep 17 – Nov 5

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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 587 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Shallot needs ~1,208 GDD — county provides 1,311 GDD Good fit

Shallot Planting Timeline โ€” Grand County, CO

Shallot Planting Calendar

Activity When Date Range
Start Indoors April 16 Apr 16 โ€“ Apr 30
Transplant Outdoors May 28 May 28 โ€“ Jun 11
Direct Sow May 21 May 21 โ€“ Jun 11
Fall Sowing June 27 Jun 27 โ€“ Jul 11
Harvest August 27 Aug 27 โ€“ Oct 15

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 Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing
August Harvest
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

114 days

Growing Tips for Grand 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 Grand County, CO?

Grand County is in Zone 4a with an average last frost of May 28. Plan your Shallot planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is May 28 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

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