One of the best tools that you have as gardeners to help us estimate 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.

A way of estimating when it's possible to plant black radish is to examine the USDA zone info for Princeton.

Planting Calendar for Black radish

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

Since black radish are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant black radish in Princeton 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 fully mature. You can get started a couple of weeks earlier by starting your black radish indoors.

Last Frost Date

The average date of last frost is May 15 in Princeton. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Princeton is an average the actual date of last frost is different every year. Since half of the time in Princeton last frost occurs after May 15 be ready to cover your black radish in the event of a late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Princeton

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