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When to plant Cucumber in Dubuque County, IA

Spring Cucumber in Dubuque County goes in May 6–May 27, once nighttime temps stop dipping near freezing.

When to Plant Cucumber in Dubuque County, IA

Dubuque County, Iowa Zone 5a July

Dubuque County, Iowa gardeners: here's your July plan

Your Dubuque County, Iowa garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost April 29
Avg. first frost October 9
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. It's harvest week for cucumber

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Before August arrives, get these ready
  • First harvests: 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.

Dubuque County, Iowa is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 9, giving you a growing season of approximately 163 days.

At an elevation of 1,243 feet, Dubuque County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Cucumber to ensure they mature before fall.

Dubuque County, IA (Zone 5a) Moderate season
163 days
Last Spring Frost April 29
163 growing days
First Fall Frost October 9

Dubuque County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Cucumber Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 28
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Mar 25 Transplant: May 13 🍅 Harvest: Jul 8 – Sep 2
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 10 Transplant: May 29 🍅 Harvest: Jul 24 – Sep 18

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 Dubuque County

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

Soil pH

Your soil pH (5.8–7.3) overlaps with Cucumber's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Dubuque 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 (3.9%). Annual compost additions will help Cucumber.

How to Plant Cucumber

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

Succession Planting Cucumber

3
successive plantings in your 163-day season

Sow every 5.7 weeks. Last sowing by Jul 31 to harvest before frost.

Cucumber Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,753 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 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 6.5" 3.4" 3.1" 💧 Light watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.8" 1.7" 💧 Light watering
Jul 6.5" 4.3" 2.2" 💧 Light watering
Aug 6.5" 3.5" 3" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 3.3" 3.2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dubuque 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 ~735 GDD — county provides 1,996 GDD Excellent fit

Cucumber Planting Timeline — Dubuque County, IA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest July 8 Jul 8 – Sep 2

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5a

📆 Growing Season

163 days in Dubuque County

Growing Tips for Cucumber in Dubuque County

Direct sow Cucumber outdoors after April 29 in Dubuque 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.

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 Dubuque County, IA?

Dubuque County is in Zone 5a with an average last frost of April 29. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dubuque County, IA?

Dubuque County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 9.

When should I plant Cucumber in Dubuque County, IA?

In Dubuque County, IA, plant Cucumber after the last frost (around April 29) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Dubuque County, IA for Cucumber?

Dubuque County sits in USDA Zone 5a. Cucumber grows reliably in zones 3a through 11b, so it's a good fit here.

Can Cucumber grow in Dubuque County's climate?

Yes — Cucumber grows well in Dubuque County's temperate climate. Dubuque County averages a 163-day frost-free season, with last frost around April 29 and first frost around October 9.

🌱

Your Dubuque County Garden Planner — Free

A 22-page printable planner built for Dubuque County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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