When to Plant Sweet Corn in Highlands County, FL
Top priorities for Highlands County, Florida gardeners in May
Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.
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Harvest sweet corn as they ripen
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
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.
Highlands County, Florida is in USDA Zone 9b. The average last spring frost is January 29 and the first fall frost is December 20, giving you a growing season of approximately 325 days.
At an elevation of 111 feet, Highlands County receives approximately 57.6 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.
Highlands County Soil Profile
Soil Type
Sand
Soil pH
4.9-5.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Highlands County
How your county's soil matches Sweet Corn's growing requirements.
Soil pH
Your soil pH (4.9–5.8) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Highlands 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
Succession Planting Sweet Corn
Sow every 6.9 weeks. Last sowing by Sep 21 to harvest before frost.
Plant Water Budget
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 | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Feb | 6.5" | 3.1" | 3.4" | 🚿 Regular watering |
| Mar | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Apr | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| May | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Jun | 6.5" | 8.5" | 0" | ✅ Rainfall sufficient |
| Jul | 6.5" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 6.5" | 9.1" | 0" | ✅ Rainfall sufficient |
| Sep | 6.5" | 8" | 0" | ✅ Rainfall sufficient |
| Oct | 6.5" | 5.1" | 1.4" | 💧 Light watering |
| Nov | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Dec | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
Water needs are for active growing months only (Jan–Dec in Highlands 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 Planting Timeline — Highlands County, FL
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 5 | Feb 5 – Feb 26 |
| Harvest | April 9 | Apr 9 – May 21 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | — |
| April | Harvest |
| May | Harvest |
| June | — |
| 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
325 days in Highlands County
Growing Tips for Sweet Corn in Highlands County
Direct sow Sweet Corn outdoors after January 29 in Highlands County when soil has warmed and frost danger has passed.
Sandy soil in Highlands 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
Check more plant combinations with our Companion Planting Checker →
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in Highlands County, FL?
Highlands County is in Zone 9b with an average last frost of January 29. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Highlands County, FL?
Highlands County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 29 and first fall frost is December 20.
Your Highlands County Garden Planner — Free
A 24-page printable planner built for Highlands 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.