The USDA Zone info is a great tool for gardeners to help us figure out 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 Thief River Falls should be looked at to determine when you can plant larkspur.

Planting Calendar for Larkspur

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

Larkspur do well in cold which means that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant larkspur 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 larkspur and expect a good harvest is probably August. You probably don't want to wait any later than that or else your larkspur may not have a chance to grow to maturity. If you are starting your larkspur indoors then you might be able to get away with starting them a couple of weeks earlier.

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 can expect an average low temperature of -35°F.

Always keep in mind that USDA zone info for Thief River Falls is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Thief River Falls it frosts late in the year after May 15 be ready to cover your larkspur in the event of 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.