The USDA Zone info is a great tool for gardeners to help us estimate 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.

You should be able to estimate when it's the best time to plant spearmint by using the USDA zone info for Marshfield.

Planting Calendar for Spearmint

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

Spearmint are very cold tolerant which means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant spearmint in Marshfield 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. If you wait any later than that and your spearmint may not have a chance to grow to maturity. If you are starting your spearmint indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Marshfield. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Marshfield is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Marshfield there is a last frost after April 15 so be sure to be ready to protect your spearmint if you have one of those late frosts.

USDA Zone Info for Marshfield

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Marshfield

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