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When to Plant Lettuce in Dolores County, CO

Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

Dolores County, Colorado is in USDA Zone 5a. The average last spring frost is June 18 and the first fall frost is September 8, giving you a growing season of approximately 82 days.

At an elevation of 7,506 feet, Dolores County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Lettuce during the growing season.

Dolores County, CO (Zone 5a) Very short season
82 days
Last Spring Frost June 18
82 growing days
First Fall Frost September 8

Dolores County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 3 Transplant: Jun 7 🍅 Harvest: Jul 12 – Sep 20
Recommended (50%) ✗ May not fit
Start indoors: May 14 Transplant: Jun 18 🍅 Harvest: Jul 23 – Oct 1
Safe Start (90%) ✗ May not fit
Start indoors: May 25 Transplant: Jun 29 🍅 Harvest: Aug 3 – Oct 12

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Lettuce needs ~619 GDD — county provides 1,127 GDD Excellent fit

Lettuce Planting Timeline โ€” Dolores County, CO

Lettuce Planting Calendar

Activity When Date Range
Start Indoors May 14 May 14 โ€“ May 28
Transplant Outdoors June 18 Jun 18 โ€“ Jul 2
Direct Sow June 4 Jun 4 โ€“ Jun 25
Fall Sowing June 30 Jun 30 โ€“ Jul 14
Harvest July 23 Jul 23 โ€“ Oct 1

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
June Transplant Outdoors Direct Sow Fall Sowing
July Transplant Outdoors Fall Sowing Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

82 days

Growing Tips for Dolores County

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Companion Planting

Good Companions

Avoid Planting Near

  • Celery

Level Up Your Garden

๐ŸŒพ Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35ยฐF, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Frequently Asked Questions

When should I plant Lettuce in Dolores County, CO?

Dolores County is in Zone 5a with an average last frost of June 18. Plan your Lettuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dolores County, CO?

Dolores County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 18 and first fall frost is September 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dolores County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Dolores County, CO. Local conditions may vary. Last updated: April 2026.