One of the best tools that you have as gardeners to help us estimate 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 checking out the USDA zone info for Havre it's possible to determine when it's the best time to plant torenia.

Planting Calendar for Torenia

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

It's probably a bad idea to plant torenia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant torenia in Havre 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. You probably don't want to wait any later than that or else your torenia may not have a chance to fully mature. You can get started a few weeks earlier by starting your torenia indoors.

Last Frost Date

In Havre the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Havre and it will vary from year to year. Half of the time in Havre it frosts late in the year after May 15 so make sure that you are prepared to protect your torenia if you have a late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

You may be interested in your other planting guides for Havre.