One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Zone 3a can be read to determine when it's a good idea to 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 tend to make it in a little bit of cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant black radish in Zone 3a 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 grow to maturity. If you are starting your black radish indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 3a. It might get as low as -40°F during the coldest months of winter.

Since the USDA zone info for Zone 3a may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Zone 3a you get a frost after May 15 so be sure to be ready to cover your black radish in the event of a surprise late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-40°F
Highest Expected Low	-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.