When to Plant Sunflowers
Sunflowers are a tender warm-season flower. Frost damages them, so they go out only after the last spring frost.
Sow them outdoors from the last spring frost to 3 weeks after it. The first flowers open about 60 to 90 days after sowing.
Example dates
The same rules in dates for three climates, using typical frost dates. Enter your ZIP code above for the dates where you live.
| Task | Last frost Mar 15first Nov 15 | Last frost Apr 15first Oct 25 | Last frost May 15first Sep 30 |
|---|---|---|---|
| Sow outdoors | Mar 15 – Apr 5 | Apr 15 – May 6 | May 15 – Jun 5 |
| In flower | May 14 – Jun 11 | Jun 14 – Jul 12 | Jul 14 – Aug 11 |
Growing sunflowers
Sow directly where they will grow; tall types may need staking in windy spots.
- Spacing: 18 in apart, in rows 30 in apart. In a raised bed, 1 per 2 sq ft at square-foot spacing.
- Days to first flowers: 60 to 90 from sowing, then about 4 weeks of flowers.
- Traditional companions: cherry tomato, cucumber, sweet corn, tomato. See companion plants for sunflowers.
- Usually kept apart from: potato.
Plan your beds with these dates
Draw your beds, tap squares to plant sunflowers and everything else, and get every crop's dates for your ZIP code in one calendar. Free, in your browser.
Open the garden plannerQuestions
Can sunflowers go in before the last frost?
No. Sunflowers are damaged by frost: sow them from the last spring frost to 3 weeks after it.
How long do sunflowers take to grow?
About 60 to 90 days from sowing to the first flowers, which then lasts about 4 weeks. Varieties differ: check the seed packet.
More planting dates
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (annual/seasonal, by station: freeze dates at 32 °F)
- NC State Extension: Extension Gardener Handbook, Chapter 16: Vegetable Gardening
- Iowa State: Germination Requirements for Annuals and Vegetables
- UC Master Gardener Program, UC ANR: Companion Planting Chart: Companion Planting for Edible Crops
- Oregon State University Extension Service: Herbs and Flowers in the Vegetable Garden
- Utah State University Extension, Utah 4-H: Creating Sustainable School and Home Gardens: Companion Planting (2025)
- University of Arizona Cooperative Extension, Yavapai County: The Art of Companion Planting (Master Gardener presentation, 2023)