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When to Plant Cucumber in Lyon County, IA

Lyon County, Iowa Zone 5a May

May in Lyon County, Iowa — your action list

Your garden in Lyon County, Iowa is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 2
Avg. first frost October 2
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.5 hrs
  1. Get cucumber in the ground

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Direct-sow cucumber

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Get ahead of June
  • Starting indoors: 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.

Lyon County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 2, giving you a growing season of approximately 153 days.

At an elevation of 1,045 feet, Lyon County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Cucumber to ensure they mature before fall.

Lyon County, IA (Zone 5a) Moderate season
153 days
Last Spring Frost May 2
153 growing days
First Fall Frost October 2

Lyon County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Jul 6 – Aug 31
Recommended (50%) ✓ Fits season (27 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Jul 11 – Sep 5
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Apr 11 Transplant: May 30 🍅 Harvest: Jul 25 – Sep 19

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 Lyon County

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

Soil pH

Your soil pH (6.3–6.8) is within Cucumber's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Cucumber will thrive.

How to Plant Cucumber

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

Succession Planting Cucumber

3
successive plantings in your 153-day season

Sow every 5.7 weeks. Last sowing by Jul 24 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,087 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 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 4.2" 2.3" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 2.7" 3.8" 🚿 Regular watering
Sep 6.5" 2.3" 4.2" 🚿 Regular watering
Oct 6.5" 2.5" 4" 🚿 Regular watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Lyon 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 ~600 GDD — county provides 1,530 GDD Excellent fit

Cucumber Planting Timeline — Lyon County, IA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest July 11 Jul 11 – Sep 5

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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

153 days in Lyon County

Growing Tips for Cucumber in Lyon County

Direct sow Cucumber outdoors after May 02 in Lyon 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 Lyon County, IA?

Lyon County is in Zone 5a with an average last frost of May 2. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lyon County, IA?

Lyon County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 2.

🌱

Your Lyon County Garden Planner — Free

A 24-page printable planner built for Lyon 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.

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 Lyon County, IA. 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.