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When to plant Salsify in Boulder County, CO

For Salsify in Boulder County, the safe spring window opens around April 30 and closes around May 21. Last expected frost is May 14, first fall frost September 26, giving a 135-day growing season. A second sowing from July 18 to August 1 extends the harvest into fall.

When to Plant Salsify in Boulder County, CO

Salsify is a root vegetable with a subtle oyster-like flavor, earning it the nickname "oyster plant." It produces long, slender, cream-colored roots.

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 Salsify 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

Salsify Planting Timeline — Boulder County, CO

Salsify Planting Calendar

Activity When Date Range
Direct Sow April 30 Apr 30 – May 21
Harvest August 13 Aug 13 – Sep 24
Fall Sowing July 18 Jul 18 – Aug 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

100–130 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 in deeply worked, stone-free soil. Use fresh seed only as viability drops quickly. Harvest in late fall after frost for best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Salsify in Boulder County, CO?

Boulder County is in Zone 6a with an average last frost of May 14. Plan your Salsify 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 Salsify in Boulder County, CO?

In Boulder County, CO, plant Salsify 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 Salsify?

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

Can Salsify grow in Boulder County's climate?

Yes — Salsify 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.

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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: July 2026.

Sources & credits

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