Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to estimate when to plant napa cabbage by looking at the USDA zone info for Iowa City.

Planting Calendar for Napa cabbage

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

You can plant napa cabbage earlier in the year because they do well in cold.

The earliest that you can plant napa cabbage 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 napa cabbage and expect a good harvest is probably September. You probably don't want to wait any later than that or else your napa cabbage may not have a chance to really do well. If you are starting your napa cabbage indoors then you might be able to get away with starting them a little bit 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.

Since the USDA zone info for Iowa City is an average the actual date of last frost can change quite a bit 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 napa cabbage 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.