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When to Plant Zucchini in Teller County, CO

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Teller County, Colorado is in USDA Zone 5a. The average last spring frost is May 11 and the first fall frost is October 6, giving you a growing season of approximately 148 days.

At an elevation of 6,538 feet, Teller County receives approximately 19.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Zucchini to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Zucchini successfully. Mulch heavily to conserve soil moisture.

Teller County, CO (Zone 5a) Short season
148 days
Last Spring Frost May 11
148 growing days
First Fall Frost October 6

Teller County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (27 days to spare)
Start indoors: Mar 30 Transplant: May 18 🍅 Harvest: Jul 6 – Aug 31
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Apr 6 Transplant: May 25 🍅 Harvest: Jul 13 – Sep 7
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Apr 22 Transplant: Jun 10 🍅 Harvest: Jul 29 – Sep 23

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 706 gal / 100 sq ft
Drought risk

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

Zucchini needs ~682 GDD — county provides 1,924 GDD Excellent fit

Zucchini Planting Timeline โ€” Teller County, CO

Zucchini Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 โ€“ Apr 20
Transplant Outdoors May 25 May 25 โ€“ Jun 8
Direct Sow May 18 May 18 โ€“ Jun 8
Harvest July 13 Jul 13 โ€“ Sep 7

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5a

Growing Season

148 days

Growing Tips for Teller County

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Zucchini in Teller County, CO?

Teller County is in Zone 5a with an average last frost of May 11. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Teller County, CO?

Teller County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 11 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Teller 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 Teller County, CO. Local conditions may vary. Last updated: April 2026.