When to plant Sunflower in Duval County, FL
In Zone 9b (Duval County), direct-sow Sunflower between January 27 and February 17 for spring, after the February 24 last-frost mark.
When to Plant Sunflower in Duval County, FL
July in Duval County, Florida — your action list
Your Duval County, Florida garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.
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Harvest sunflower as they ripen
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Get ahead of August
- First harvests: sunflower
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.
Duval County, Florida is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is November 29, giving you a growing season of approximately 278 days.
At an elevation of 337 feet, Duval County receives approximately 56.9 inches of rainfall annually with predominantly sand soil. Summer highs average 102°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.
Duval County Soil Profile
Soil Type
Sand
Soil pH
5-5.8
Drainage
Well Drained
Sunflower 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 Duval County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.0–5.8) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in Duval County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (1.4%). Add 2-3 inches of compost before planting Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Aug 21 to harvest before frost.
Sunflower Water Budget
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 | — | 2.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 8.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Duval 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 Planting Timeline — Duval County, FL
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 3 | Feb 3 – Feb 17 |
| Transplant Outdoors | January 27 | Jan 27 – Feb 10 |
| Direct Sow | January 27 | Jan 27 – Feb 17 |
| Bloom | April 21 | Apr 21 – Oct 6 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| 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 9b
📆 Growing Season
278 days in Duval County
Growing Tips for Sunflower in Duval County
Direct sow Sunflower outdoors after February 24 in Duval County when soil has warmed and frost danger has passed.
Sandy soil in Duval 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 102°F in Duval 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 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Duval County, FL?
Duval County is in Zone 9b with an average last frost of February 24. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Duval County, FL?
Duval County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is November 29.
When should I plant Sunflower in Duval County, FL?
In Duval County, FL, plant Sunflower after the last frost (around February 24) and before the first frost (around November 29). Best results when soil holds above 50°F.
What growing zone is Duval County, FL for Sunflower?
Duval County sits in USDA Zone 9b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in Duval County's climate?
Yes — Sunflower grows well in Duval County's temperate climate. Duval County averages a 279-day frost-free season, with last frost around February 24 and first frost around November 29.
Your Duval County Garden Planner — Free
A 22-page printable planner built for Duval 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.