When to Plant Sunflower in Zone 4
Helianthus annuus
Last updated: Apr 25, 2026 · Sources: USDA, NOAA, Cooperative ExtensionZone 4 Planting Schedule
Direct Sow
May 24
Directly in garden bed
First Harvest
Aug 12
70–100 days after planting
Season Ends
Sep 22
Before first frost (Sep 25)
Quick Facts
Sunlight
☀️ Full Sun
Water Needs
💧 Low
Spacing
24 inches apart
Planting Depth
1.0 inch
Min Soil Temp
55°F
Germination
7–14 days
Days to Maturity
70–100 days
Frost Tolerance
No frost tolerance
Soil pH
6.0–7.5
Difficulty
Easy
Recommended for Zone 4
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Companion planting improves growth, deters pests, and makes better use of garden space.
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Potato
Sunflower Schedule — All Zones
| Zone | Start Indoors | Transplant | Direct Sow | Harvest Start | Harvest End |
|---|---|---|---|---|---|
| Zone 2 | — | — | Jun 8 | Aug 27 | Sep 2 |
| Zone 3 | — | — | May 29 | Aug 17 | Sep 12 |
| Zone 4 | — | — | May 24 | Aug 12 | Sep 22 |
| Zone 5 | — | — | May 14 | Aug 2 | Oct 1 |
| Zone 6 | — | — | Apr 29 | Jul 18 | Sep 16 |
| Zone 7 | — | — | Apr 19 | Jul 8 | Sep 6 |
| Zone 8 | — | — | Apr 3 | Jun 22 | Aug 21 |
| Zone 9 | — | — | Mar 14 | Jun 2 | Aug 1 |
| Zone 10 | — | — | Feb 24 | May 15 | Jul 14 |
| Zone 11 | — | — | Jan 29 | Apr 19 | Jun 18 |
📚 Data Sources
Frost dates: NOAA Climate Normals 1991–2020, National Centers for Environmental Information.Hardiness zones: USDA Plant Hardiness Zone Map, Agricultural Research Service.
Growing requirements: Cooperative Extension Services — NC State, Penn State, University of Florida IFAS.
Companion planting: Cornell University Cooperative Extension.
Data compiled from public agricultural sources. Always verify with your local extension office for micro-climate adjustments.