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When to plant Shallot in Denver County, CO

Denver County gardeners should plant Shallot between April 30 and May 21 in spring. With Denver County's Zone 6a climate (last frost May 14), Shallot needs 90–120 days to mature — plant by May 29 for a full harvest. A second sowing from July 18 to August 1 extends the harvest into fall.

When to Plant Shallot in Denver 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.

Denver County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 6,818 feet, Denver County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Shallot during the growing season.

Denver County, CO (Zone 6a) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Denver County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Shallot Planting Timeline — Denver County, CO

Shallot Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow April 30 Apr 30 – May 21
Harvest August 13 Aug 13 – Oct 1
Fall Sowing July 18 Jul 18 – Aug 1

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Denver County

Growing Tips for Denver 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Shallot in Denver County, CO?

Denver County is in Zone 6a with an average last frost of May 14. Plan your Shallot planting based on this frost date — see the calendar above for exact timing.

What planting zone is Denver County, CO?

Denver County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Shallot in Denver County, CO?

In Denver County, CO, plant Shallot after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Denver County, CO for Shallot?

Denver County sits in USDA Zone 6a. Shallot grows reliably in zones 4a through 10b, so it's a good fit here.

Can Shallot grow in Denver County's climate?

Yes — Shallot grows well in Denver County's temperate climate. Denver County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

🌱

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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 Denver County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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