Blog

When to plant Sunflower in Jackson County, FL

In Zone 9a (Jackson County), direct-sow Sunflower between February 13 and March 6 for spring, after the March 6 last-frost mark.

When to Plant Sunflower in Jackson County, FL

Jackson County, Florida Zone 9a July

Your July planting checklist for Jackson County, Florida

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

Avg. last frost March 6
Avg. first frost November 19
Soil temp (4") 91°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Basket week: sunflower

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

August will be here before you know it — start on
  • First harvests: sunflower

Instant PDF download. No spam, unsubscribe any time.

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Jackson County, Florida is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 19, giving you a growing season of approximately 258 days.

At an elevation of 223 feet, Jackson County receives approximately 48.5 inches of rainfall annually with predominantly sand soil. Summer highs average 92°F, providing good warmth for Sunflower during the growing season. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Jackson County, FL (Zone 9a) Long season
258 days
Last Spring Frost March 6
258 growing days
First Fall Frost November 19

Jackson County Soil Profile

Soil Type

Sand

Soil pH

5.1-6

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Feb 7 Transplant: Feb 7 🌸 Bloom: May 2 – Oct 3
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Feb 13 Transplant: Feb 13 🌸 Bloom: May 8 – Oct 9
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Mar 6 Transplant: Mar 6 🌸 Bloom: May 29 – Oct 30

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 Jackson County

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

Soil pH

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

Soil Texture

Sandy soil in Jackson 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 (1.3%). Add 2-3 inches of compost before planting Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sunflower

4
successive plantings in your 258-day season

Sow every 8 weeks. Last sowing by Aug 11 to harvest before frost.

Sunflower Water Budget

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

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

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 2.3" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.2" 2.7" 0" ✅ Rainfall sufficient
Apr 2.2" 1.9" 0.3" 💧 Light watering
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 7" 0" ✅ Rainfall sufficient
Jul 2.2" 7.2" 0" ✅ Rainfall sufficient
Aug 2.2" 7.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.1" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Jackson 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 ~1,615 GDD — county provides 4,902 GDD Excellent fit

Sunflower Planting Timeline — Jackson County, FL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow February 13 Feb 13 – Mar 6
Bloom May 8 May 8 – Oct 9

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

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 9a

📆 Growing Season

258 days in Jackson County

Growing Tips for Sunflower in Jackson County

Direct sow Sunflower outdoors after March 06 in Jackson County when soil has warmed and frost danger has passed.

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

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 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Jackson County, FL?

Jackson County is in Zone 9a with an average last frost of March 6. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, FL?

Jackson County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 19.

When should I plant Sunflower in Jackson County, FL?

In Jackson County, FL, plant Sunflower after the last frost (around March 6) and before the first frost (around November 19). Best results when soil holds above 50°F.

What growing zone is Jackson County, FL for Sunflower?

Jackson County sits in USDA Zone 9a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Jackson County's climate?

Yes — Sunflower grows well in Jackson County's temperate climate. Jackson County averages a 258-day frost-free season, with last frost around March 6 and first frost around November 19.

🌱

Your Jackson County Garden Planner — Free

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

Sources & credits

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