One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Fort Madison should be used to determine when you can plant sunflowers.

Planting Calendar for Sunflowers

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

Sunflowers do not do well in cold weather which means that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sunflowers in Fort Madison 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. Any later than that and your sunflowers may not have a chance to fully mature. If you are starting your sunflowers indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Fort Madison. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Fort Madison is not always accurate the actual date of last frost is different every year. Half of the time in Fort Madison you get a frost after April 15 so make sure that you are prepared to cover your sunflowers in the event of a late frost.

USDA Zone Info for Fort Madison

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Fort Madison

You may be interested in your other planting guides for Fort Madison.