One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. 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 figure out when it's a good idea to plant hosta by reviewing the USDA zone info for Iowa City.

Planting Calendar for Hosta

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

You can plant hosta a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant hosta 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 hosta and expect a good harvest is probably September. Any later than that and your hosta may not have a chance to grow to maturity. If you are starting your hosta indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

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 is different every year. Half of the time in Iowa City there is a last frost after April 15 so always be ready to protect your hosta if you have 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.