How to Grow Sunflower (2026)
Direct sow after frost; support tall types.
Quick answer: Sunflower is a warm-season crop for zones 3–12 in full sun. Plant after the last frost, space 18″ apart, and expect harvest in about 80 days.
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In Alabama (zone 7–9, last frost ≈ Mar 15, first frost ≈ Nov 15, 245-day season), your Sunflower plan:
Direct sow after frost; support tall types. Suits USDA zones 3–12. Dates are typical; confirm with your county extension and the 10-day forecast.
Growing tips
- Spacing: 18 inches between plants keeps air flowing and limits disease.
- Depth: sow seeds about 1″ deep (or set transplants at the same soil line).
- Sun: Full sun (6+ hours).
- Season: Wait until nights stay above 55°F and soil is warm.
Spacing & planting FAQ
Common sunflower problems
Symptoms, likely causes, fixes and prevention — each page is printable.
More warm-season crops
Spacing, depth, and days-to-harvest are typical values from university extension guides. Planting dates are computed from typical USDA/extension freeze dates (USDA Plant Hardiness Zone Map (2023) + state cooperative extension typical freeze dates); confirm locally before acting.