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When to Plant Sunflower in Clay County, FL

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.

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 Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

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 (155 days to spare)
Start indoors: Dec 29 Transplant: Feb 16 🍅 Harvest: Apr 27 – Jun 15
Recommended (50%) ✓ Fits season (156 days to spare)
Start indoors: Jan 7 Transplant: Feb 25 🍅 Harvest: May 6 – Jun 24
Safe Start (90%) ✓ Fits season (147 days to spare)
Start indoors: Feb 8 Transplant: Mar 29 🍅 Harvest: Jun 7 – Jul 26

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 Sunflower's growing requirements.

Soil pH

Your soil pH (5.0โ€“5.8) is more acidic than Sunflower prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Clay 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 (1.6%). 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

4
successive plantings in your 282-day season

Sow every 8 weeks. Last sowing by Aug 19 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~2,061 GDD — county provides 6,862 GDD Excellent fit

Sunflower Planting Timeline โ€” Clay County, FL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 โ€“ Jan 21
Transplant Outdoors February 25 Feb 25 โ€“ Mar 11
Direct Sow February 18 Feb 18 โ€“ Mar 11
Harvest May 6 May 6 โ€“ Jun 24

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
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

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

282 days in Clay County

Growing Tips for Sunflower in Clay County

Direct sow Sunflower 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 Sunflower 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 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Clay County, FL?

Clay County is in Zone 9a with an average last frost of February 18. Plan your Sunflower 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.