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When to Plant Cucumber in Moffat County, CO

Moffat County, Colorado Zone 5b May

What to do in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost June 7
Avg. first frost September 14
Soil temp (4") 39°F
Watering High
Pest pressure Low
Daylight 14.3 hrs
Before June arrives, get these ready
  • Transplants going out: cucumber
  • Direct-sowing: cucumber

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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.

Moffat County, Colorado is in USDA Zone 5b. The average last spring frost is June 7 and the first fall frost is September 14, giving you a growing season of approximately 99 days.

At an elevation of 6,597 feet, Moffat County receives approximately 12.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, 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.

Moffat County, CO (Zone 5b) Very short season
99 days
Last Spring Frost June 7
99 growing days
First Fall Frost September 14

Moffat County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 23 Transplant: Jun 11 🍅 Harvest: Aug 6 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: May 3 Transplant: Jun 21 🍅 Harvest: Aug 16 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jul 4 🍅 Harvest: Aug 29 – Oct 24

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 Moffat County

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

Soil pH

Your soil pH (6.8–8.3) is more alkaline than Cucumber prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Moffat County is excellent for Cucumber — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Cucumber is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Cucumber.

How to Plant Cucumber

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

Succession Planting Cucumber

2
successive plantings in your 99-day season

Sow every 5.7 weeks. Last sowing by Jul 06 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.7″/week
Watering frequency 2-3 times/week
Season total 1,510 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 1.4" 0" ❄️ Dormant
Jun 6.5" 0.8" 5.7" 🚿 Regular watering
Jul 6.5" 1" 5.5" 🚿 Regular watering
Aug 6.5" 1.4" 5.1" 🚿 Regular watering
Sep 6.5" 1.1" 5.4" 🚿 Regular watering
Oct 1" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Moffat County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 1,435 GDD Excellent fit

Cucumber Planting Timeline — Moffat County, CO

Cucumber Planting Calendar

Activity When Date Range
Start Indoors May 3 May 3 – May 17
Transplant Outdoors June 21 Jun 21 – Jul 5
Direct Sow June 14 Jun 14 – Jul 5
Harvest August 16 Aug 16 – Oct 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

99 days in Moffat County

Growing Tips for Cucumber in Moffat County

Direct sow Cucumber outdoors after June 07 in Moffat 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.

Moffat County receives only 12" of rain annually. Cucumber needs consistent moisture — 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 Moffat County, CO?

Moffat County is in Zone 5b with an average last frost of June 7. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Moffat County, CO?

Moffat County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 7 and first fall frost is September 14.

🌱

Your Moffat County Garden Planner — Free

A 24-page printable planner built for Moffat County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.