Before planting it is a good idea to find your USDA Zone info to figure out 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 figured out 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.

You can plant spearmint much earlier in the year because they are very cold tolerant.

The earliest that you can plant spearmint 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 spearmint and expect a good harvest is probably August. Any later than that and your spearmint may not have a chance to really do well. You can get started a couple of weeks earlier by starting your spearmint indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Watertown. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Watertown and it is different every year. Since half of the time in Watertown last frost occurs after May 15 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 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Watertown

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