Blog

When to plant Sweet Corn in Putnam County County,

Spring Sweet Corn in Putnam County County goes in February 16–March 9, once nighttime temps stop dipping near freezing.

When to Plant Sweet Corn in Putnam County, FL

Putnam County, Florida Zone 9b June

Your June game plan for Putnam County, Florida

A quick June briefing for Putnam County, Florida gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 9
Avg. first frost December 2
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Bring in the sweet corn

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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.

Putnam County, Florida is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.

At an elevation of 278 feet, Putnam County receives approximately 57.5 inches of rainfall annually with predominantly sand soil. Summer highs average 95°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.

Putnam County, FL (Zone 9b) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2

Putnam County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.2

Drainage

Well Drained

Sweet Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (199 days to spare)
Transplant: Jan 25 🍅 Harvest: Mar 29 – May 10
Recommended (50%) ✓ Fits season (191 days to spare)
Transplant: Feb 9 🍅 Harvest: Apr 13 – May 25
Safe Start (90%) ✓ Fits season (192 days to spare)
Transplant: Mar 4 🍅 Harvest: May 6 – Jun 17

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 Putnam County

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

Soil pH

Your soil pH (4.9–6.2) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Putnam 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 (1.4%). 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 296-day season

Sow every 6.9 weeks. Last sowing by Sep 03 to harvest before frost.

Sweet Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,606 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 2.4" 0" ❄️ Dormant
Feb 6.5" 2.6" 3.9" 🚿 Regular watering
Mar 6.5" 3.5" 3" 💧 Light watering
Apr 6.5" 2.3" 4.2" 🚿 Regular watering
May 6.5" 3.3" 3.2" 💧 Light watering
Jun 6.5" 7.9" 0" ✅ Rainfall sufficient
Jul 6.5" 9.4" 0" ✅ Rainfall sufficient
Aug 6.5" 8.7" 0" ✅ Rainfall sufficient
Sep 6.5" 7.4" 0" ✅ Rainfall sufficient
Oct 6.5" 5.3" 1.2" 💧 Light watering
Nov 6.5" 2.2" 4.3" 🚿 Regular watering
Dec 6.5" 2.6" 3.9" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Putnam 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 ~1,594 GDD — county provides 6,311 GDD Excellent fit

Sweet Corn Planting Timeline — Putnam County, FL

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow February 16 Feb 16 – Mar 9
Harvest April 20 Apr 20 – Jun 1

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 · 2-3 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

296 days in Putnam County

Growing Tips for Sweet Corn in Putnam County

Direct sow Sweet Corn outdoors after February 09 in Putnam County when soil has warmed and frost danger has passed.

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

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 Putnam County, FL?

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

What planting zone is Putnam County, FL?

Putnam County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 2.

When should I plant Sweet Corn in Putnam County, ?

In Putnam County, , plant Sweet Corn after the last frost (around February 9) and before the first frost (around December 2). Best results when soil holds above 50°F.

What growing zone is Putnam County, for Sweet Corn?

Putnam County sits in USDA Zone 9b. Sweet Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Corn grow in Putnam County's climate?

Yes — Sweet Corn grows well in Putnam County's temperate climate. Putnam County averages a 297-day frost-free season, with last frost around February 9 and first frost around December 2.

🌱

Your Putnam County Garden Planner — Free

A 22-page printable planner built for Putnam County (Zone 9b). 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 Putnam County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.