One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. 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 Thief River Falls can be reviewed to figure out when you can plant foxglove.

Planting Calendar for Foxglove

Frost tolerance for foxglove:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Foxglove are moderately cold tolerant which means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant foxglove in Thief River Falls 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 foxglove and expect a good harvest is probably August. Any later than that and your foxglove may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your foxglove indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Thief River Falls. In the coldest months of winter you should expect an average low temperature of -35°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Thief River Falls and it changes from year to year. Since half of the time in Thief River Falls you get surprised by a frost after May 15 be ready to cover your foxglove if you have a surprise late frost.

USDA Zone Info for Thief River Falls

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Thief River Falls

You may be interested in your other planting guides for Thief River Falls.