Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 Janesville it's a good idea to estimate when it's possible to plant hollyhocks.

Planting Calendar for Hollyhocks

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

Hollyhocks are moderately cold tolerant which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant hollyhocks in Janesville 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 hollyhocks and expect a good harvest is probably September. If you wait any later than that and your hollyhocks may not have a chance to fully mature. If you are starting your hollyhocks indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Janesville. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Janesville is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Janesville last frost occurs after April 15 be ready to cover your hollyhocks in the event of one of those late frosts.

USDA Zone Info for Janesville

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Janesville

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