One of the first steps you take when you are making a decision about 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.

You will be able to figure out when you can plant pearl onions by referring to the USDA zone info for Janesville.

Planting Calendar for Pearl onions

Frost tolerance for pearl onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Pearl onions do ok in some cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pearl onions in Janesville is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant pearl onions and expect a good harvest is probably August. Any later than that and your pearl onions may not have a chance to really do well. Starting your pearl onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Janesville. In the coldest months of winter you should 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 changes from year to year. Half of the time in Janesville last frost occurs after April 15 so be sure to be ready to cover your pearl onions if you have 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.