One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Iowa City you can determine when it's the best time to plant basil by reviewing the USDA zone info.

Planting Calendar for Basil

Frost tolerance for basil:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant basil 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 basil 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 basil and expect a good harvest is probably August. Any later than that and your basil may not have a chance to grow to maturity. Starting your basil indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Iowa City the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Iowa City is an average the actual date of last frost changes from year to year. Half of the time in Iowa City it frosts late in the year after April 15 so make sure that you are prepared to cover your basil in the event of 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.