When to Plant Radishes in Janesville, WI

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant radishes in Janesville by referring to the USDA zone info.


Planting Calendar for Radishes

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

Since radishes do well in cold you can plant them earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant radishes
Possibly ok, but a risky time to plant radishes
Probably not a good time to plant radishes

The earliest that you can plant radishes 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 radishes and expect a good harvest is probably September. If you wait any later than that and your radishes may not have a chance to really do well. If you are starting your radishes indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Janesville. It might get as low as -20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Janesville and it changes from year to year. Half of the time in Janesville you get a frost after April 15 so make sure that you are prepared to cover your radishes 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.