The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Watertown you can estimate when to plant black radish by reviewing the USDA zone info.

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 ok in some cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant black radish in Watertown 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. If you wait any later than that and your black radish may not have a chance to fully mature. 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

In Watertown the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Watertown may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Watertown there is a last frost after May 15 be ready to protect your black radish if you have a surprise late frost.

USDA Zone Info for Watertown

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 Watertown

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