Before planting it is a good idea to find your USDA Zone info to estimate 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.

You will be able to determine when it's the best time to plant spearmint by reviewing the USDA zone info for Baltimore.

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 pretty solid cold which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant spearmint in Baltimore 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. Any later than that and your spearmint may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your spearmint indoors.

Last Frost Date

The average date of last frost is April 15 in Baltimore. 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 an average because it is based on the USDA zone info for Baltimore and it changes from year to year. Half of the time in Baltimore you get surprised by a frost after April 15 so always be ready to cover your spearmint in the event of one of those late frosts.

USDA Zone Info for Baltimore

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Baltimore

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