Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Thief River Falls you can determine when it's a good idea to plant bougainvillea by referring to the USDA zone info.

Planting Calendar for Bougainvillea

Frost tolerance for bougainvillea:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Bougainvillea do not do well in cold weather which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

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

Last Frost Date

In Thief River Falls the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -35°F.

Just be sure to remember 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. Half of the time in Thief River Falls there is a last frost after May 15 so always be ready to protect your bougainvillea in the event of a 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.