Blog

When to Plant Sweet Corn in Houston County, MN

Houston County, Minnesota Zone 5a May

May to-do list for Houston County, Minnesota

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

Avg. last frost May 3
Avg. first frost October 6
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Plant sweet corn from seed, right in the garden

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

Instant PDF download. No spam, unsubscribe any time.

Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Houston County, Minnesota is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 6, giving you a growing season of approximately 156 days.

At an elevation of 558 feet, Houston County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sweet Corn to ensure they mature before fall.

Houston County, MN (Zone 5a) Moderate season
156 days
Last Spring Frost May 3
156 growing days
First Fall Frost October 6
Share this guide:

Houston County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Transplant: Apr 27 🍅 Harvest: Jun 29 – Aug 10
Recommended (50%) ✓ Fits season (51 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Aug 16
Safe Start (90%) ✓ Fits season (46 days to spare)
Transplant: May 18 🍅 Harvest: Jul 20 – Aug 31

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 Houston County

How your county's soil matches Sweet Corn's growing requirements.

Soil pH

Your soil pH (6.0–7.0) is within Sweet Corn's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Sweet Corn will thrive.

How to Plant Sweet Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Sweet Corn

3
successive plantings in your 156-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.1″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 625 gal / 100 sq ft

Monthly Watering Guide for Sweet Corn

Sweet Corn 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 Sweet Corn Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 4.8" 1.7" 💧 Light watering
Jul 6.5" 4.8" 1.7" 💧 Light watering
Aug 6.5" 4.5" 2" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 3" 3.5" 🚿 Regular watering
Nov 2.8" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Sweet Corn 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.

Sweet Corn needs ~919 GDD — county provides 1,911 GDD Excellent fit

Sweet Corn Planting Timeline — Houston County, MN

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 10 May 10 – May 31
Harvest July 12 Jul 12 – Aug 23

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June
July Harvest
August Harvest
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

156 days in Houston County

Growing Tips for Sweet Corn in Houston County

Direct sow Sweet Corn outdoors after May 03 in Houston County when soil has warmed and frost danger has passed.

Common pests for Sweet Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Houston County, MN?

Houston County is in Zone 5a with an average last frost of May 3. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Houston County, MN?

Houston County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 6.

🌱

Your Houston County Garden Planner — Free

A 24-page printable planner built for Houston 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 Houston County, MN. 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.