Planting Dates for Colorado

Colorado's high altitude and intense sunshine create unique gardening challenges and opportunities. The Front Range has the most moderate conditions, while mountain communities face very short growing seasons.

USDA Zones 3a-7a • 60-165 frost-free days depending on location

Frost Dates in Colorado

Average last spring frost and first fall frost dates for Colorado cities. Use these to calculate your planting windows.

CityLast Spring FrostFirst Fall FrostFrost-Free DaysUSDA Zone
DenverMay 4Oct 61556a
Colorado SpringsMay 6Oct 21495b
Grand JunctionApr 22Oct 141757a

Gardening Tips for Colorado

  • ✓High altitude intensifies sun — plants may need afternoon shade protection.
  • ✓Front Range gardens (Denver area) enjoy about 155 frost-free days.
  • ✓Mountain gardens above 7,000 feet can see frost any month of the year.
  • ✓Colorado's dry climate requires consistent irrigation for vegetable gardens.

What to Plant in Colorado

Cold-Hardy Crops (plant early)

These crops tolerate frost and can be planted 2-6 weeks before your last frost date.

LettuceSemi-Hardy

30-60 days from sowing

PeasHardy

55-70 days from sowing

CarrotsSemi-Hardy

60-80 days from sowing

KaleHardy

50-70 days from sowing

BroccoliSemi-Hardy

55-80 days from transplant

SpinachHardy

35-50 days from sowing

RadishesHardy

20-35 days from sowing

GarlicHardy

July-August the following year

OnionsHardy

90-120 days from transplant

PotatoesSemi-Hardy

70-120 days from planting

BeetsSemi-Hardy

50-70 days from sowing

Swiss ChardSemi-Hardy

50-60 days from sowing

Warm-Season Crops (plant after last frost)

Start these indoors and transplant after all frost danger has passed.

TomatoesVery Tender

60-85 days from transplant

PeppersVery Tender

60-90 days from transplant

BeansTender

50-65 days from sowing

CucumbersVery Tender

50-65 days from sowing

Zucchini & Summer SquashTender

45-60 days from sowing

CornTender

60-100 days from sowing

Herbs (Basil, Cilantro, Dill)Tender

30-60 days from sowing

Get Exact Planting Dates for Colorado

Enter your city's frost date and get precise seed starting, transplant, and harvest dates for 38+ vegetables — free.

Frequently Asked Questions

When is the last frost date in Colorado?

Last frost dates in Colorado vary by city: Denver (May 4), Colorado Springs (May 6), Grand Junction (Apr 22).

What USDA hardiness zones are in Colorado?

Colorado spans USDA hardiness zones 3a-7a. Your specific zone determines which perennials survive winter and when to start planting annuals.

What vegetables grow best in Colorado?

Hardy crops like peas, kale, spinach, and garlic thrive across Colorado. In warmer zones, tomatoes, peppers, and cucumbers do well with proper timing. Use our free calculator for exact planting dates.

How long is the growing season in Colorado?

60-165 frost-free days depending on location. Extend your season with cold frames, row covers, and indoor seed starting.

Planting Dates by State

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