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When to plant Caraway in Boulder County, CO

Boulder County sits in USDA Zone 6a. Plant Caraway between April 30 (after last frost on May 14) and May 21. A second sowing from July 18 to August 1 extends the harvest into fall.

When to Plant Caraway in Boulder County, CO

Caraway is a biennial herb grown for its distinctive crescent-shaped seeds used in rye bread, sauerkraut, and European cuisine. The leaves and roots are also edible.

Boulder 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 7,657 feet, Boulder County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Caraway during the growing season.

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

Boulder County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Caraway Planting Timeline — Boulder County, CO

Caraway Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Fall Sowing July 18 Jul 18 – Aug 1

Plant 0.5" deep · 8" 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
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

365–450 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Boulder County

Growing Tips for Boulder County

Direct sow in spring or fall. Caraway produces seeds in its second year. Harvest seed heads when they turn brown. The young leaves can be used like parsley.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Caraway in Boulder County, CO?

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

What planting zone is Boulder County, CO?

Boulder 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 Caraway in Boulder County, CO?

In Boulder County, CO, plant Caraway 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 Boulder County, CO for Caraway?

Boulder County sits in USDA Zone 6a. Caraway grows reliably in zones 3a through 9b, so it's a good fit here.

Can Caraway grow in Boulder County's climate?

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

🌱

Your Boulder County Garden Planner — Free

A 22-page printable planner built for Boulder County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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