Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant spearmint in Watertown can be estimated by using the USDA zone info.

Planting Calendar for Spearmint

Frost tolerance for spearmint:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Spearmint do well in cold which tells us that you can start planting them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant spearmint in Watertown is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant spearmint and expect a good harvest is probably September. You probably don't want to wait any later than that or else your spearmint may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your spearmint indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Watertown. You should expect an average low temperature of -20°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Watertown and it will vary from year to year. Half of the time in Watertown last frost occurs after April 15 so be sure to be ready to cover your spearmint in the event of a surprise late frost.

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.