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

In Duluth you can estimate when it's a good idea to plant thyme by reviewing the USDA zone info.

Planting Calendar for Thyme

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

Thyme are very cold tolerant which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant thyme in Duluth 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 thyme and expect a good harvest is probably August. You probably don't want to wait any later than that or else your thyme may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your thyme indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Duluth. It might get as low as -30°F during the coldest months of winter.

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 Duluth and it changes from year to year. Half of the time in Duluth it frosts late in the year after May 15 so be sure to be ready to cover your thyme in the event of a surprise late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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