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When to Plant Sweet Corn in Assumption Parish, LA

Assumption Parish, Louisiana Zone 9b May

Your May game plan for Assumption Parish, Louisiana

A quick May briefing for Assumption Parish, Louisiana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 13
Avg. first frost December 5
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for sweet corn

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

A few tasks this May that'll pay off in June
  • First harvests: sweet corn

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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.

Assumption Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.

At an elevation of 126 feet, Assumption Parish receives approximately 55.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 104°F, so Sweet Corn may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Corn will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Corn root diseases.

Assumption Parish, LA (Zone 9b) Year-round
295 days
Last Spring Frost February 13
295 growing days
First Fall Frost December 5

Assumption Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (191 days to spare)
Transplant: Feb 4 🍅 Harvest: Apr 8 – May 20
Recommended (50%) ✓ Fits season (190 days to spare)
Transplant: Feb 13 🍅 Harvest: Apr 17 – May 29
Safe Start (90%) ✓ Fits season (181 days to spare)
Transplant: Mar 9 🍅 Harvest: May 11 – Jun 22

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 Assumption Parish

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

Soil pH

Your soil pH (5.0–6.3) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Assumption Parish warms quickly in spring but drains fast. Sweet Corn will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Sweet Corn.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Sweet Corn.

How to Plant Sweet Corn

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

Succession Planting Sweet Corn

5
successive plantings in your 295-day season

Sow every 6.9 weeks. Last sowing by Sep 06 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 684 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 4.4" 0" ❄️ Dormant
Feb 6.5" 4.6" 1.9" 💧 Light watering
Mar 6.5" 5.5" 1" 💧 Light watering
Apr 6.5" 4.3" 2.2" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.8" 1.7" 💧 Light watering
Jul 6.5" 6.2" 0.3" 💧 Light watering
Aug 6.5" 5" 1.5" 💧 Light watering
Sep 6.5" 3.9" 2.6" 💧 Light watering
Oct 6.5" 3.8" 2.7" 💧 Light watering
Nov 6.5" 4.2" 2.3" 💧 Light watering
Dec 6.5" 4.6" 1.9" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Assumption Parish). 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 ~2,100 GDD — county provides 8,288 GDD Excellent fit

Sweet Corn Planting Timeline — Assumption Parish, LA

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow February 20 Feb 20 – Mar 13
Harvest April 24 Apr 24 – Jun 5

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

295 days in Assumption Parish

Growing Tips for Sweet Corn in Assumption Parish

Direct sow Sweet Corn outdoors after February 13 in Assumption Parish when soil has warmed and frost danger has passed.

Sandy soil in Assumption Parish dries quickly — mulch Sweet Corn with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 104°F in Assumption Parish, provide afternoon shade for Sweet Corn and water deeply in the morning.

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 Assumption Parish, LA?

Assumption Parish is in Zone 9b with an average last frost of February 13. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Assumption Parish, LA?

Assumption Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 5.

🌱

Your Assumption Parish Garden Planner — Free

A 24-page printable planner built for Assumption Parish (Zone 9b). 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 Assumption Parish, LA. 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.