Blog

When to Plant Melon in Monroe County, IA

Monroe County, Iowa Zone 5b May

May to-do list for Monroe County, Iowa

Each item below is timed to Monroe County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 26
Avg. first frost October 13
Soil temp (4") 58°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Transplant melon outside

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Put melon seeds straight in the ground

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

  3. Indoor seed-starting week for melon

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Instant PDF download. No spam, unsubscribe any time.

Melons are warm-season vine crops that produce sweet, juicy fruits in many varieties including muskmelon and honeydew. They need a long, hot growing season.

Monroe County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 13, giving you a growing season of approximately 170 days.

At an elevation of 968 feet, Monroe County receives approximately 32.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Melon during the growing season.

Monroe County, IA (Zone 5b) Moderate season
170 days
Last Spring Frost April 26
170 growing days
First Fall Frost October 13
Share this guide:

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Mar 14 Transplant: May 2 🍅 Harvest: Jul 11 – Aug 29
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Mar 22 Transplant: May 10 🍅 Harvest: Jul 19 – Sep 6
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Aug 5 – 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.

Soil Compatibility in Monroe County

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

Soil pH

Your soil pH (6.2–7.3) overlaps with Melon's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Melon will thrive.

How to Plant Melon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Melon

2
successive plantings in your 170-day season

Sow every 8 weeks. Last sowing by Jul 05 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 298 gal / 100 sq ft

Monthly Watering Guide for Melon

Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Melon Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Monroe County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Melon 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.

Melon needs ~1,296 GDD — county provides 2,592 GDD Excellent fit

Melon Planting Timeline — Monroe County, IA

Melon Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest July 19 Jul 19 – Sep 6

Plant 1" deep · 30" apart · Rows 42" 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
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

170 days in Monroe County

Growing Tips for Melon in Monroe County

Direct sow Melon outdoors after April 26 in Monroe County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors 3-4 weeks before transplanting. Plant on raised mounds of compost-enriched soil. Reduce watering as fruits ripen to concentrate sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Cucumber

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Melon in Monroe County, IA?

Monroe County is in Zone 5b with an average last frost of April 26. Plan your Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, IA?

Monroe County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 13.

🌱

Your Monroe County Garden Planner — Free

A 24-page printable planner built for Monroe 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 Monroe 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.