One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 can figure out when you can plant black radish in Superior by looking at the USDA zone info.

Planting Calendar for Black radish

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

Black radish do ok in mild cold which means that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant black radish in Superior 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 black radish and expect a good harvest is probably August. Any later than that and your black radish may not have a chance to really do well. You can get started a little bit earlier by starting your black radish indoors.

Last Frost Date

The average date of last frost is May 15 in Superior. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Superior is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Superior there is a last frost after May 15 so be sure to be ready to protect your black radish in the event of one of those late frosts.

USDA Zone Info for Superior

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Superior

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