One of the first steps you take when you are determining 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.

The USDA zone info for Louisville should be used to figure out when you can plant black radish.

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 plant them earlier than other frost tender plants.

The earliest that you can plant black radish in Louisville 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. If you wait any later than that and your black radish may not have a chance to grow to maturity. If you are starting your black radish indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Louisville. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that USDA zone info for Louisville may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Louisville last frost occurs after April 15 so make sure that you are ready to protect your black radish if you have one of those late frosts.

USDA Zone Info for Louisville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Louisville

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