One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 figure out when to plant regal geranium by looking at the USDA zone info.

Planting Calendar for Regal Geranium

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

Regal Geranium do ok in moderate cold which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant regal geranium 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 regal geranium and expect a good harvest is probably August. Any later than that and your regal geranium may not have a chance to fully mature. You can get started a few weeks earlier by starting your regal geranium indoors.

Last Frost Date

The average date of last frost is May 15 in Thief River Falls. In the coldest months of winter you can expect an average low temperature of -35°F.

Since the USDA zone info for Thief River Falls is not always accurate the actual date of last frost is different every year. Half of the time in Thief River Falls you get a frost after May 15 so always be ready to protect your regal geranium 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.