One of the best tools that you have as gardeners to help us determine 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 should be able to determine when it's possible to plant black radish by checking out the USDA zone info for Rock Falls.

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 well in moderate cold which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

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

Last Frost Date

The average date of last frost is April 15 in Rock Falls. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rock Falls and it can change quite a bit from year to year. Half of the time in Rock Falls it frosts late in the year after April 15 so make sure that you are prepared to cover your black radish if you have a late frost.

USDA Zone Info for Rock Falls

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rock Falls

You may be interested in your other planting guides for Rock Falls.