Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant sunflowers in Sioux Falls should be determined by referring to the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost.

Sunflowers require warm weather which tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant sunflowers in Sioux Falls is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to grow to maturity. Starting your sunflowers indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on May 15 in Sioux Falls. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Sioux Falls and it can change quite a bit from year to year. Half of the time in Sioux Falls you get surprised by a frost after May 15 so make sure that you are prepared to cover your sunflowers in the event of one of those late frosts.

USDA Zone Info for Sioux Falls

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Sioux Falls

You may be interested in your other planting guides for Sioux Falls.