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When to Plant Mustard Greens in Archuleta County, CO

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Archuleta County, Colorado is in USDA Zone 5b. The average last spring frost is June 13 and the first fall frost is September 17, giving you a growing season of approximately 96 days.

At an elevation of 5,346 feet, Archuleta County receives approximately 14 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Mustard Greens during the growing season. With low rainfall, drip irrigation is essential for growing Mustard Greens successfully. Mulch heavily to conserve soil moisture.

Archuleta County, CO (Zone 5b) Very short season
96 days
Last Spring Frost June 13
96 growing days
First Fall Frost September 17

Archuleta County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 11 – Sep 12
Recommended (50%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Jul 29 – Sep 30

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
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 397 gal / 100 sq ft
Drought risk

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

Mustard Greens needs ~550 GDD — county provides 1,320 GDD Excellent fit

Mustard Greens Planting Timeline โ€” Archuleta County, CO

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 โ€“ May 23
Transplant Outdoors June 13 Jun 13 โ€“ Jun 27
Direct Sow May 30 May 30 โ€“ Jun 20
Fall Sowing July 9 Jul 9 โ€“ Jul 23
Harvest July 18 Jul 18 โ€“ Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

96 days

Growing Tips for Archuleta County

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Mustard Greens in Archuleta County, CO?

Archuleta County is in Zone 5b with an average last frost of June 13. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Archuleta County, CO?

Archuleta County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 13 and first fall frost is September 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Archuleta County gardeners in Zone 5b 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 Archuleta County, CO. Local conditions may vary. Last updated: April 2026.