Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant black radish by looking at the USDA zone info for Groton.

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 are moderately cold tolerant which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant black radish in Groton 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. You probably don't want to wait any later than that or else 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 Groton. It might get as low as -5°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 Groton and it can change quite a bit from year to year. Half of the time in Groton you get a frost after April 15 so make sure that you are ready to protect your black radish in the event of a late frost.

USDA Zone Info for Groton

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 Groton

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