One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 marigold in Iowa City can be determined by checking out the USDA zone info.

Planting Calendar for Marigold

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

Since marigold do not do well in cold weather it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant marigold in Iowa City 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 marigold and expect a good harvest is probably August. If you wait any later than that and your marigold may not have a chance to fully mature. You can get started a few weeks earlier by starting your marigold indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Iowa City. You can expect an average low temperature of -15°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Iowa City and it changes from year to year. Since half of the time in Iowa City you get a frost after April 15 be ready to cover your marigold in the event of one of those late frosts.

USDA Zone Info for Iowa City

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 Iowa City

You may be interested in your other planting guides for Iowa City.