One of the best tools that you have as gardeners to help us figure out 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.

A way of figuring out when it's a good idea to plant bee balm is to consult the USDA zone info for Iowa City.

Planting Calendar for Bee Balm

Frost tolerance for bee balm:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bee Balm are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can start planting them slightly earlier than other frost tender plants.

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

The last month that you can plant bee balm and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bee balm may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your bee balm indoors.

Last Frost Date

On average the last frost is on April 15 in Iowa City. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Iowa City is just an average the actual date of last frost changes from year to year. Half of the time in Iowa City there is a last frost after April 15 so be sure to be ready to cover your bee balm if you have a 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.