Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Watertown should be reviewed to figure out when it's possible to plant sweet potatos.

Planting Calendar for Sweet Potatos

Frost tolerance for sweet potatos:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since sweet potatos do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sweet potatos in Watertown is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sweet potatos and expect a good harvest is probably August. Any later than that and your sweet potatos may not have a chance to fully mature. Starting your sweet potatos indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Watertown the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Watertown and it can change quite a bit from year to year. Half of the time in Watertown you get surprised by a frost after April 15 so make sure that you are ready to cover your sweet potatos in the event of a late frost.

USDA Zone Info for Watertown

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 Watertown

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