The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant thyme in Iowa City should be estimated by checking out the USDA zone info.

Planting Calendar for Thyme

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

Since thyme are very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant thyme 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 thyme and expect a good harvest is probably September. Any later than that and your thyme may not have a chance to really do well. You can get started a few weeks earlier by starting your thyme indoors.

Last Frost Date

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

Just be sure to remember 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 is different every year. Since half of the time in Iowa City last frost occurs after April 15 be ready to cover your thyme 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.