Before planting it is a good idea to find your USDA Zone info to determine 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.

You will be able to determine when you can plant oregano by referring to the USDA zone info for Iowa City.

Planting Calendar for Oregano

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

Oregano do well in mild cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant oregano 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 oregano and expect a good harvest is probably September. If you wait any later than that and your oregano may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your oregano indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Iowa City. 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 just an average the actual date of last frost changes from year to year. Since half of the time in Iowa City there is a last frost after April 15 be ready to cover your oregano 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.