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When to Plant Sweet Corn in Clay County, FL

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.

Clay County, Florida is in USDA Zone 9a. The average last spring frost is February 18 and the first fall frost is November 27, giving you a growing season of approximately 282 days.

At an elevation of 122 feet, Clay County receives approximately 54.3 inches of rainfall annually with predominantly sand soil. Summer highs average 99ยฐF, so Sweet Corn may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Clay County, FL (Zone 9a) Year-round
282 days
Last Spring Frost February 18
282 growing days
First Fall Frost November 27

Clay County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (176 days to spare)
Transplant: Feb 9 🍅 Harvest: Apr 13 – May 25
Recommended (50%) ✓ Fits season (177 days to spare)
Transplant: Feb 18 🍅 Harvest: Apr 22 – Jun 3
Safe Start (90%) ✓ Fits season (168 days to spare)
Transplant: Mar 22 🍅 Harvest: May 24 – Jul 5

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 Clay County

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

Soil pH

Your soil pH (5.0โ€“5.8) is more acidic than Sweet Corn prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Clay County 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 low (1.6%). Add 2-3 inches of compost before planting 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 282-day season

Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,882 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 โ€” 2.6" 0" โ„๏ธ Dormant
Feb 6.5" 3" 3.5" ๐Ÿšฟ Regular watering
Mar 6.5" 3.1" 3.4" ๐Ÿšฟ Regular watering
Apr 6.5" 2.5" 4" ๐Ÿšฟ Regular watering
May 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Jun 6.5" 8.5" 0" โœ… Rainfall sufficient
Jul 6.5" 7.4" 0" โœ… Rainfall sufficient
Aug 6.5" 7.4" 0" โœ… Rainfall sufficient
Sep 6.5" 6.6" 0" โœ… Rainfall sufficient
Oct 6.5" 5.1" 1.4" ๐Ÿ’ง Light watering
Nov 6.5" 2.1" 4.4" ๐Ÿšฟ Regular watering
Dec โ€” 2.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Clay County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,819 GDD — county provides 6,862 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Clay County, FL

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow February 25 Feb 25 โ€“ Mar 18
Harvest April 29 Apr 29 โ€“ Jun 10

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

282 days in Clay County

Growing Tips for Sweet Corn in Clay County

Direct sow Sweet Corn outdoors after February 18 in Clay County when soil has warmed and frost danger has passed.

Sandy soil in Clay County dries quickly โ€” 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 99ยฐF in Clay County, 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 Clay County, FL?

Clay County is in Zone 9a with an average last frost of February 18. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clay County, FL?

Clay County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 18 and first fall frost is November 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clay County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Clay County, FL. Local conditions may vary. Last updated: April 2026.