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.

You can determine when you can plant napa cabbage in Janesville by referring to the USDA zone info.

Planting Calendar for Napa cabbage

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

Napa cabbage tend to make it in cold weather which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant napa cabbage 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 napa cabbage and expect a good harvest is probably September. You probably don't want to wait any later than that or else your napa cabbage may not have a chance to fully mature. If you are starting your napa cabbage indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Janesville the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Janesville may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Janesville you get surprised by a frost after April 15 be ready to protect your napa cabbage 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.