When to plant Sunflower in St. Clair County, AL
The best window to plant Sunflower in St. Clair County, is March 20–April 10, when soil warms to 50°F. Last frost typically hits March 27; first frost November 1.
When to Plant Sunflower in St. Clair County, AL
June in St. Clair County, Alabama — your action list
June is a pivotal month for St. Clair County, Alabama gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Bring in the sunflower
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Looking ahead to July
- 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.
St. Clair County, Alabama is in USDA Zone 8a. The average last spring frost is March 27 and the first fall frost is November 1, giving you a growing season of approximately 219 days.
At an elevation of 211 feet, St. Clair County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89°F, providing good warmth for Sunflower during the growing season. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot.
St. Clair County Soil Profile
Soil Type
Clay Loam
Soil pH
5.3-6.8
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 St. Clair County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.3–6.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
The clay loam soil in St. Clair County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 24 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 | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 3.6" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in St. Clair 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 — St. Clair County, AL
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | March 20 | Mar 20 – Apr 3 |
| Direct Sow | March 20 | Mar 20 – Apr 10 |
| Bloom | June 12 | Jun 12 – Oct 16 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| 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: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
219 days in St. Clair County
Growing Tips for Sunflower in St. Clair County
Direct sow Sunflower outdoors after March 27 in St. Clair County when soil has warmed and frost danger has passed.
With St. Clair County's clay soil (26% clay), work in 3-4 inches of compost before planting Sunflower. Avoid tilling when soil is wet to prevent compaction.
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 St. Clair County, AL?
St. Clair County is in Zone 8a with an average last frost of March 27. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, AL?
St. Clair County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 27 and first fall frost is November 1.
When should I plant Sunflower in St. Clair County, AL?
In St. Clair County, AL, plant Sunflower after the last frost (around March 27) and before the first frost (around November 1). Best results when soil holds above 50°F.
What growing zone is St. Clair County, AL for Sunflower?
St. Clair County sits in USDA Zone 8a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in St. Clair County's climate?
Yes — Sunflower grows well in St. Clair County's temperate climate. St. Clair County averages a 219-day frost-free season, with last frost around March 27 and first frost around November 1.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.