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.

You should be able to figure out when it's the best time to plant creeping phlox by checking out the USDA zone info for Iowa City.

Planting Calendar for Creeping Phlox

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

Creeping Phlox do well in cold weather which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant creeping phlox 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 creeping phlox and expect a good harvest is probably September. Any later than that and your creeping phlox may not have a chance to fully mature. You can get started a little bit earlier by starting your creeping phlox indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Iowa City. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Iowa City and it will vary from year to year. Half of the time in Iowa City you get surprised by a frost after April 15 so make sure that you are prepared to cover your creeping phlox in the event of 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.