Blog

When to Plant Cucumber in Chaffee County, CO

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Chaffee County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,788 feet, Chaffee County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Cucumber during the growing season. With low rainfall, drip irrigation is essential for growing Cucumber successfully. Mulch heavily to conserve soil moisture.

Chaffee County, CO (Zone 5a) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Chaffee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 6 Transplant: Jun 24 🍅 Harvest: Aug 19 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: May 12 Transplant: Jun 30 🍅 Harvest: Aug 25 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: May 22 Transplant: Jul 10 🍅 Harvest: Sep 4 – Oct 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.

Soil Compatibility in Chaffee County

How your county's soil matches Cucumber's growing requirements.

Soil pH

Your soil pH (6.7โ€“7.6) is more alkaline than Cucumber prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Chaffee County is excellent for Cucumber โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Cucumber.

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 495 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Cucumber

Cucumber needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cucumber Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 1.8" 0" โ„๏ธ Dormant
May โ€” 2.4" 0" โ„๏ธ Dormant
Jun 6.5" 1.4" 5.1" ๐Ÿšฟ Regular watering
Jul 6.5" 1.8" 4.7" ๐Ÿšฟ Regular watering
Aug 6.5" 1.9" 4.6" ๐Ÿšฟ Regular watering
Sep 6.5" 1.4" 5.1" ๐Ÿšฟ Regular watering
Oct โ€” 1.5" 0" โ„๏ธ Dormant
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Chaffee County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cucumber Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cucumber needs ~870 GDD — county provides 1,203 GDD Excellent fit

Cucumber Planting Timeline โ€” Chaffee County, CO

Cucumber Planting Calendar

Activity When Date Range
Start Indoors May 12 May 12 โ€“ May 26
Transplant Outdoors June 30 Jun 30 โ€“ Jul 14
Direct Sow June 23 Jun 23 โ€“ Jul 14
Harvest August 25 Aug 25 โ€“ Oct 20

Plant 0.5" deep ยท 24" apart ยท Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

83 days in Chaffee County

Growing Tips for Cucumber in Chaffee County

Direct sow Cucumber outdoors after June 16 in Chaffee County when soil has warmed and frost danger has passed.

Common pests for Cucumber in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

Chaffee County receives only 19" of rain annually. Cucumber needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Chaffee County, CO?

Chaffee County is in Zone 5a with an average last frost of June 16. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chaffee County, CO?

Chaffee County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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