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.

By checking out the USDA zone info for Iowa City it's a good idea to figure out when you can plant flax.

Planting Calendar for Flax

Frost tolerance for flax:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Flax do well in moderate cold which means that you can plant them earlier than plants that are more sensitive to the cold.

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

Last Frost Date

The average date of last frost is April 15 in Iowa City. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Iowa City and it can change quite a bit from year to year. Half of the time in Iowa City it frosts late in the year after April 15 so be sure to be ready to protect your flax 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.