One of the first steps you take when you are estimating 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.

The USDA zone info for Janesville can be reviewed to determine when it's the best time to plant hosta.

Planting Calendar for Hosta

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

Hosta do well in moderate cold which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant hosta 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 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. You can get started a little bit earlier by starting your hosta indoors.

Last Frost Date

The average date of last frost is April 15 in Janesville. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Janesville and it is different every year. Half of the time in Janesville you get a frost after April 15 so always be ready to protect your hosta if you have a late frost.

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.