When to Plant Common hollyhock in Iowa City, IA

One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Iowa City you should be able to estimate when it's the best time to plant common hollyhock.


Planting Calendar for Common hollyhock

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

Common hollyhock are moderately cold tolerant which means that you can plant them a little bit earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant common hollyhock
Possibly ok, but a risky time to plant common hollyhock
Probably not a good time to plant common hollyhock

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

Last Frost Date

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

Always keep in mind that the actual date of last frost is an average 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 you get surprised by a frost after April 15 so be sure to be ready to protect your common hollyhock if you have one of those late frosts.

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.