One of the best tools that you have as gardeners to help us determine 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 USDA zone info for Iowa City can be reviewed to estimate when it's the best time to plant hardy hibiscus.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant hardy hibiscus earlier in the year because they are very cold tolerant.

The earliest that you can plant hardy hibiscus 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 hardy hibiscus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to grow to maturity. Starting your hardy hibiscus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Iowa City is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Iowa City you get surprised by a frost after April 15 be ready to protect your hardy hibiscus 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.