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When to Plant Sunflower in Hernando County, FL

Hernando County, Florida Zone 9b May

This month in Hernando County, Florida

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost January 25
Avg. first frost December 16
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 13.4 hrs
  1. Harvest sunflower as they ripen

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

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Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Hernando County, Florida is in USDA Zone 9b. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 245 feet, Hernando County receives approximately 51.5 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Hernando County, FL (Zone 9b) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16

Hernando County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (199 days to spare)
Start indoors: Dec 8 Transplant: Jan 26 🍅 Harvest: Apr 6 – May 25
Recommended (50%) ✓ Fits season (199 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Apr 12 – May 31
Safe Start (90%) ✓ Fits season (173 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: May 16 – Jul 4

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 Hernando County

How your county's soil matches Sunflower's growing requirements.

Soil pH

Your soil pH (5.1–5.9) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Hernando County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

5
successive plantings in your 325-day season

Sow every 8 weeks. Last sowing by Sep 07 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sunflower

Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan 2.2" 2.6" 0" ✅ Rainfall sufficient
Feb 2.2" 2.5" 0" ✅ Rainfall sufficient
Mar 2.2" 3" 0" ✅ Rainfall sufficient
Apr 2.2" 2.2" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 7.1" 0" ✅ Rainfall sufficient
Jul 2.2" 7.5" 0" ✅ Rainfall sufficient
Aug 2.2" 6.7" 0" ✅ Rainfall sufficient
Sep 2.2" 6.8" 0" ✅ Rainfall sufficient
Oct 2.2" 5.1" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 2.2" 2.2" 0" ✅ Rainfall sufficient

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

Sunflower 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.

Sunflower needs ~2,061 GDD — county provides 7,905 GDD Excellent fit

Sunflower Planting Timeline — Hernando County, FL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors December 14 Dec 14 – Dec 28
Transplant Outdoors February 1 Feb 1 – Feb 15
Direct Sow January 25 Jan 25 – Feb 15
Harvest April 12 Apr 12 – May 31

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

325 days in Hernando County

Growing Tips for Sunflower in Hernando County

Direct sow Sunflower outdoors after January 25 in Hernando County when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in Hernando County, provide afternoon shade for Sunflower and water deeply in the morning.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Hernando County, FL?

Hernando County is in Zone 9b with an average last frost of January 25. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hernando County, FL?

Hernando County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 25 and first fall frost is December 16.

🌱

Your Hernando County Garden Planner — Free

A 24-page printable planner built for Hernando 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.

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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 Hernando County, FL. 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.