The USDA Zone info is a great tool for gardeners to help us determine your gardening 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 Washington can be looked at to determine when to plant spearmint.

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 means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant spearmint in Washington 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 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 March 15 in Washington. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Washington is just an average the actual date of last frost is different every year. Half of the time in Washington it frosts late in the year after March 15 so always be ready to protect your spearmint in the event of a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Washington

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