Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when you can plant hardy hibiscus by reviewing the USDA zone info for Janesville.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus 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 hardy hibiscus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

On average the last frost is on April 15 in Janesville. You can expect an average low temperature of -20°F in the coldest months of winter.

Keep in mind that USDA zone info for Janesville is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Janesville you get a frost after April 15 so make sure that you are ready to cover your hardy hibiscus 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.