The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when it's possible to plant torenia in River Falls by using the USDA zone info.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since torenia are not cold tolerant you really should wait until after the last frost before you can plant them.

The earliest that you can plant torenia in 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 torenia and expect a good harvest is probably August. If you wait any later than that and your torenia may not have a chance to grow to maturity. If you are starting your torenia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In River Falls the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for River Falls is an average and the actual date of last frost is different every year. Half of the time in River Falls you get a frost after May 15 so just be sure to be ready to cover your torenia if you have a surprise late frost.

USDA Zone Info for River Falls

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in River Falls

You may be interested in your other planting guides for River Falls.