The USDA Zone info is a great tool for gardeners to help us determine 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.

The USDA zone info for Watertown can be looked at to determine when it's possible to plant tomatos.

Planting Calendar for Tomatos

Frost tolerance for tomatos:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant tomatos until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant tomatos 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 tomatos and expect a good harvest is probably August. If you wait any later than that and your tomatos may not have a chance to really do well. You can get started a few weeks earlier by starting your tomatos indoors.

Last Frost Date

On average the last frost is on April 15 in Watertown. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Watertown may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Watertown it frosts late in the year after April 15 be ready to protect your tomatos if you have one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Watertown

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