One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Thief River Falls you should be able to figure out when it's the best time to plant tropical hibiscus.

Planting Calendar for Tropical Hibiscus

Frost tolerance for tropical hibiscus:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant tropical hibiscus until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant tropical hibiscus 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 tropical hibiscus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tropical hibiscus may not have a chance to really do well. Starting your tropical hibiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on 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 may not be accurate from year to year and the actual date of last frost can change quite a bit 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 protect your tropical hibiscus if you have 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.