When to Plant Sunflowers in Missouri
Few things bring more joy than a row of sunflowers turning their faces to the sun. Easy, dramatic, and pollinator-friendly.
The Short Answer
Missouri Frost Dates
Your planting dates depend on which part of Missouri you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Missouri | 5b, 6a | Apr 20 - May 5 | Oct 1 - Oct 15 |
| Central Missouri | 6a, 6b | Apr 10 - Apr 25 | Oct 10 - Oct 25 |
| Southern Missouri | 6b, 7a | Apr 1 - Apr 15 | Oct 15 - Nov 1 |
Sunflowers Planting Schedule for Missouri
Northern Missouri (Zones 5b, 6a)
Average last frost: Apr 20 - May 5 · Average first frost: Oct 1 - Oct 15
Central Missouri (Zones 6a, 6b)
Average last frost: Apr 10 - Apr 25 · Average first frost: Oct 10 - Oct 25
Southern Missouri (Zones 6b, 7a)
Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 15 - Nov 1
Growing Sunflowers in Missouri
Sunflowers in Missouri's Climate
Sunflowers are nearly foolproof in moderate climates. Direct sow after frost and watch them grow a foot or more per week in the summer heat. Succession plant every 2 weeks through late June for blooms all summer. Your reliable warm season gives even the tallest mammoth varieties plenty of time to mature.
Soil Considerations for Missouri
Rich loess soils along Missouri River. Rocky Ozark soils in south. Heavy clay common. Generally fertile. Make sure soil has warmed to at least 55°F before planting sunflowers outside.
Missouri Climate & Growing Season
Continental climate. Hot, humid summers. Four seasons. Good growing season in most of state. Sunflowers cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Missouri: Northern Missouri (5b, 6a) has a last frost around Apr 20 - May 5, while Southern Missouri (6b, 7a) sees frost end around Apr 1 - Apr 15. This difference matters for sunflowers — transplant timing shifts by several weeks across the state.
Growing Tips
Direct sow is preferred — sunflowers don't love transplanting. Succession plant every 2 weeks for blooms all summer.
Companion Planting
Plant sunflowers alongside these companions for better growth:
Keep sunflowers away from:
The Bottom Line
Last reviewed: March 29, 2026