One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's a good idea to plant black eyed susans is to check out the USDA zone info for Iowa City.

Planting Calendar for Black Eyed Susans

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

Black Eyed Susans do not do well in cold weather which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant black eyed susans 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 black eyed susans and expect a good harvest is probably August. Any later than that and your black eyed susans may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your black eyed susans indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Iowa City and it will vary from year to year. Since half of the time in Iowa City you get surprised by a frost after April 15 be ready to cover your black eyed susans if you have 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.