When to plant sunflowers
annual
The short answer
Sunflowers are sown outdoors after the last frost. You can get a head start by starting them indoors 2 to 3 weeks before the last frost.
Zone 5: direct sow from Apr 30. Zone 7: direct sow from Apr 5. Zone 9: direct sow from Feb 20. See every zone or your state.
When to plant sunflowers by USDA zone
Dates are worked out from each zone’s typical last frost, using the number of weeks the cited extension services give. Find your zone on the zone map. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Typical last frost | Start indoors (optional) | Direct sow |
|---|---|---|---|
| Zone 3 | May 15 | Apr 24 – May 1 | from May 15 |
| Zone 4 | May 10 | Apr 19 – Apr 26 | from May 10 |
| Zone 5 | Apr 30 | Apr 9 – Apr 16 | from Apr 30 |
| Zone 6 | Apr 15 | Mar 25 – Apr 1 | from Apr 15 |
| Zone 7 | Apr 5 | Mar 15 – Mar 22 | from Apr 5 |
| Zone 8 | Mar 20 | Feb 27 – Mar 6 | from Mar 20 |
| Zone 9 | Feb 20 | Jan 30 – Feb 6 | from Feb 20 |
| Zone 10 | Jan 30 | Jan 9 – Jan 16 | from Jan 30 |
Rule used: direct sow after the last frost; start indoors (optional) 2 to 3 weeks before the last frost. Repeat every 1-2 weeks for a long bloom season (Minnesota: same variety every one to two weeks; Illinois: every one to three weeks).
When to plant sunflowers in your state
Same rule, applied to each state’s typical last spring frost. States marked * span very different climates, so use your own frost date for the exact day - click a state for its frost dates.
| State | Typical last frost | Start indoors (optional) | Direct sow |
|---|---|---|---|
| Alabama | Mar 25 | Mar 4 – Mar 11 | from Mar 25 |
| Alaska * | May 17 | Apr 26 – May 3 | from May 17 |
| Arizona * | Mar 15 | Feb 22 – Mar 1 | from Mar 15 |
| Arkansas | Apr 3 | Mar 13 – Mar 20 | from Apr 3 |
| California * | Feb 20 | Jan 30 – Feb 6 | from Feb 20 |
| Colorado | May 5 | Apr 14 – Apr 21 | from May 5 |
| Connecticut | Apr 25 | Apr 4 – Apr 11 | from Apr 25 |
| Delaware | Apr 14 | Mar 24 – Mar 31 | from Apr 14 |
| District of Columbia | Apr 10 | Mar 20 – Mar 27 | from Apr 10 |
| Florida | Feb 12 | Jan 22 – Jan 29 | from Feb 12 |
| Georgia | Mar 25 | Mar 4 – Mar 11 | from Mar 25 |
| Idaho | May 10 | Apr 19 – Apr 26 | from May 10 |
| Illinois | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| Indiana | Apr 24 | Apr 3 – Apr 10 | from Apr 24 |
| Iowa | Apr 25 | Apr 4 – Apr 11 | from Apr 25 |
| Kansas | Apr 15 | Mar 25 – Apr 1 | from Apr 15 |
| Kentucky | Apr 18 | Mar 28 – Apr 4 | from Apr 18 |
| Louisiana | Mar 5 | Feb 12 – Feb 19 | from Mar 5 |
| Maine | May 14 | Apr 23 – Apr 30 | from May 14 |
| Maryland | Apr 14 | Mar 24 – Mar 31 | from Apr 14 |
| Massachusetts | Apr 24 | Apr 3 – Apr 10 | from Apr 24 |
| Michigan | May 10 | Apr 19 – Apr 26 | from May 10 |
| Minnesota | May 6 | Apr 15 – Apr 22 | from May 6 |
| Mississippi | Mar 20 | Feb 27 – Mar 6 | from Mar 20 |
| Missouri | Apr 15 | Mar 25 – Apr 1 | from Apr 15 |
| Montana | May 15 | Apr 24 – May 1 | from May 15 |
| Nebraska | Apr 30 | Apr 9 – Apr 16 | from Apr 30 |
| Nevada * | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| New Hampshire | May 13 | Apr 22 – Apr 29 | from May 13 |
| New Jersey | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| New Mexico * | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| New York * | May 1 | Apr 10 – Apr 17 | from May 1 |
| North Carolina | Apr 5 | Mar 15 – Mar 22 | from Apr 5 |
| North Dakota | May 15 | Apr 24 – May 1 | from May 15 |
| Ohio | Apr 25 | Apr 4 – Apr 11 | from Apr 25 |
| Oklahoma | Apr 1 | Mar 11 – Mar 18 | from Apr 1 |
| Oregon * | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| Pennsylvania | May 1 | Apr 10 – Apr 17 | from May 1 |
| Rhode Island | Apr 25 | Apr 4 – Apr 11 | from Apr 25 |
| South Carolina | Mar 25 | Mar 4 – Mar 11 | from Mar 25 |
| South Dakota | May 10 | Apr 19 – Apr 26 | from May 10 |
| Tennessee | Apr 10 | Mar 20 – Mar 27 | from Apr 10 |
| Texas * | Mar 15 | Feb 22 – Mar 1 | from Mar 15 |
| Utah | May 5 | Apr 14 – Apr 21 | from May 5 |
| Vermont | May 14 | Apr 23 – Apr 30 | from May 14 |
| Virginia | Apr 15 | Mar 25 – Apr 1 | from Apr 15 |
| Washington * | Apr 20 | Mar 30 – Apr 6 | from Apr 20 |
| West Virginia | May 5 | Apr 14 – Apr 21 | from May 5 |
| Wisconsin | May 10 | Apr 19 – Apr 26 | from May 10 |
| Wyoming | May 20 | Apr 29 – May 6 | from May 20 |
What extension services say
- Direct seed sunflowers after all danger of frost has passed. University of Minnesota Extension ↗
- Illinois direct-seeds in early to mid-May, and says seed can be started indoors about 2-3 weeks before planting out for a head start. University of Illinois Extension ↗
- If direct sowing, wait until after the last frost, when soil temperatures have reached at least 50°F. In Oregon the best time is usually April to June for the Willamette Valley and the Coast, and June for Central and Eastern Oregon. Oregon State University Extension ↗
- For continuous bloom, plant the same variety at one- to two-week intervals, or varieties with different days to maturity at three- to four-week intervals. University of Minnesota Extension ↗
- Illinois suggests succession planting every 1-3 weeks. University of Illinois Extension ↗
Questions gardeners ask
When is the best time to plant sunflowers?
After all danger of frost has passed. Oregon State adds that the soil should be at least 50°F for direct sowing.
How do you get sunflowers to bloom all season?
Sow the same variety every one to two weeks, or mix varieties with different days to maturity (Minnesota Extension).
How deep do you plant sunflower seeds?
One inch deep, with about 6 inches between 2-5 ft varieties and at least 1 foot between taller ones (Minnesota Extension).
Sources
- University of Minnesota Extension: Sunflowers
- Oregon State University Extension: Grow your own sunflowers (EM 9866)
- University of Illinois Extension: How to grow sunflowers at home
Extension advice is local to the state that wrote it. Where the sources differ, both are shown. Dates in the tables are estimates from typical frost dates; your garden’s own last frost can differ by a week or more. How we source data.