The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 Iowa City should be looked at to determine when to plant black radish.

Planting Calendar for Black radish

Frost tolerance for black radish:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Black radish are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant black radish in Iowa City is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant black radish and expect a good harvest is probably September. You probably don't want to wait any later than that or else your black radish may not have a chance to really do well. You can get started a few weeks earlier by starting your black radish indoors.

Last Frost Date

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

Remember that USDA zone info for Iowa City may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Iowa City last frost occurs after April 15 so be sure to be ready to protect your black radish if you have a surprise late frost.

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.