Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when you can plant radishes is to look at the USDA zone info for Madison.

Planting Calendar for Radishes

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

Radishes do ok in pretty solid cold which means that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant radishes in Madison 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. Any later than that and your radishes may not have a chance to fully mature. If you are starting your radishes indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Madison the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Madison is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Madison you get surprised by a frost after April 15 so be sure to be ready to protect your radishes in the event of a late frost.

USDA Zone Info for Madison

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Madison

You may be interested in your other planting guides for Madison.