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 earliest that you can plant spearmint in Oregon should be determined by reviewing 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.

Since spearmint are very cold tolerant you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant spearmint in Oregon 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 fully mature. Starting your spearmint indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Oregon the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oregon and it is different every year. Half of the time in Oregon last frost occurs after April 15 so make sure that you are ready to protect your spearmint if you have one of those late frosts.

USDA Zone Info for Oregon

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 Oregon

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