The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when it's the best time to plant common hollyhock by using the USDA zone info for Coralville.

Planting Calendar for Common hollyhock

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

Since common hollyhock do well in moderate cold you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant common hollyhock in Coralville 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 common hollyhock and expect a good harvest is probably September. Any later than that and your common hollyhock may not have a chance to really do well. You can get started a little bit earlier by starting your common hollyhock indoors.

Last Frost Date

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

It's important 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 Coralville and it is different every year. Since half of the time in Coralville last frost occurs after April 15 be ready to cover your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Coralville

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 Coralville

You may be interested in your other planting guides for Coralville.