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

A common way of getting a good idea when it's possible to plant sunflowers is to look at the USDA zone info for Ankeny.

Planting Calendar for Sunflowers

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

You can not plant sunflowers until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant sunflowers in Ankeny is April. However, you really should wait until May 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. You probably don't want to wait any later than that or else your sunflowers may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sunflowers indoors.

Last Frost Date

In Ankeny the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Remember that USDA zone info for Ankeny is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Ankeny there is a last frost after April 15 so always be ready to protect your sunflowers if you have a surprise late frost.

USDA Zone Info for Ankeny

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ankeny

You may be interested in your other planting guides for Ankeny.