The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when to plant datura by looking at the USDA zone info for Thief River Falls.

Planting Calendar for Datura

Frost tolerance for datura:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Datura do well in mild cold which tells us that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant datura in Thief River Falls is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant datura and expect a good harvest is probably August. Any later than that and your datura may not have a chance to fully mature. If you are starting your datura indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Thief River Falls. It might get as low as -35°F during the coldest months of winter.

Always keep in mind that USDA zone info for Thief River Falls is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Thief River Falls last frost occurs after May 15 be ready to protect your datura 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.