When to plant Sunflower in Scott County, IL
The best window to plant Sunflower in Scott County, is April 21–May 12, when soil warms to 50°F. Last frost typically hits April 14; first frost October 17.
When to Plant Sunflower in Scott County, IL
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.
Scott County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.
At an elevation of 987 feet, Scott County receives approximately 37.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Scott County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.1
Drainage
Well Drained
Monthly Watering Guide for Sunflower
Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3" | 1.3" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Scott County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower Planting Timeline — Scott County, IL
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Bloom | July 14 | Jul 14 – Oct 6 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
186 days in Scott County
Growing Tips for Scott County
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 Scott County, IL?
Scott County is in Zone 6a with an average last frost of April 14. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Scott County, IL?
Scott County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 17.
When should I plant Sunflower in Scott County, IL?
In Scott County, IL, plant Sunflower after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Scott County, IL for Sunflower?
Scott County sits in USDA Zone 6a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in Scott County's climate?
Yes — Sunflower grows well in Scott County's temperate climate. Scott County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.
Your Scott County Garden Planner — Free
A 22-page printable planner built for Scott County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.