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When to Plant Sunflower in Palm Beach 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.

Palm Beach County, Florida is in USDA Zone 10a. The average last spring frost is February 17 and the first fall frost is April 15, giving you a growing season of approximately 57 days.

At an elevation of 355 feet, Palm Beach County receives approximately 50 inches of rainfall annually with predominantly sand soil. Summer highs average 93ยฐF, providing good warmth for Sunflower during the growing season. 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.

Palm Beach County, FL (Zone 10a) Very short season
57 days
Last Spring Frost February 17
57 growing days
First Fall Frost April 15

Palm Beach 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 (121 days to spare)
Start indoors: Dec 30 Transplant: Feb 17 🍅 Harvest: Apr 28 – Jun 16
Recommended (50%) ✓ Fits season (114 days to spare)
Start indoors: Jan 6 Transplant: Feb 24 🍅 Harvest: May 5 – Jun 23
Safe Start (90%) ✓ Fits season (107 days to spare)
Start indoors: Jan 13 Transplant: Mar 3 🍅 Harvest: May 12 – Jun 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 243 gal / 100 sq ft
Sunflower needs ~1,679 GDD — county provides 7,208 GDD Excellent fit

Sunflower Planting Timeline โ€” Palm Beach County, FL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 6 Jan 6 โ€“ Jan 20
Transplant Outdoors February 24 Feb 24 โ€“ Mar 10
Direct Sow February 17 Feb 17 โ€“ Mar 10
Harvest May 5 May 5 โ€“ Jun 23

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

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 10a

Growing Season

57 days

Growing Tips for Palm Beach County

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 Palm Beach County, FL?

Palm Beach County is in Zone 10a with an average last frost of February 17. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Palm Beach County, FL?

Palm Beach County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is February 17 and first fall frost is .

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Palm Beach County gardeners in Zone 10a 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 Palm Beach County, FL. Local conditions may vary. Last updated: April 2026.