When to Plant Sunflower in Miami-Dade County, FL
This month in Miami-Dade County, Florida
Your garden in Miami-Dade County, Florida is working on a schedule, even when you're not. Here's where you should be this May.
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.
Miami-Dade County, Florida is in USDA Zone 11a. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.
At an elevation of 123 feet, Miami-Dade County receives approximately 58.7 inches of rainfall annually with predominantly sand soil. Summer highs average 90°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
Miami-Dade County Soil Profile
Soil Type
Sand
Soil pH
5.1-6.3
Drainage
Well Drained
Plant 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 Miami-Dade County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.1–6.3) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in Miami-Dade 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
Plant 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 | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Feb | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 8.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 9.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 7.1" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 5" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in Miami-Dade 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 — Miami-Dade County, FL
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | November 20 | Nov 20 – Dec 4 |
| Transplant Outdoors | January 8 | Jan 8 – Jan 22 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Harvest | March 19 | Mar 19 – May 7 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | — |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | Start Indoors |
| 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 11a
📆 Growing Season
364 days in Miami-Dade County
Growing Tips for Sunflower in Miami-Dade County
Sandy soil in Miami-Dade 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 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Miami-Dade County, FL?
Miami-Dade County is in Zone 11a with an average last frost of January 1. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Miami-Dade County, FL?
Miami-Dade County, Florida is in USDA Hardiness Zone 11a. The average last spring frost is January 1 and first fall frost is December 31.
Your Miami-Dade County Garden Planner — Free
A 24-page printable planner built for Miami-Dade County (Zone 11a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.