One of the first steps you take when you are figuring out your gardening schedule is find your 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 Havre you should be able to determine when you can plant liatris.

Planting Calendar for Liatris

Frost tolerance for liatris:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Liatris do well in cold which means that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant liatris in Havre is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant liatris and expect a good harvest is probably August. Any later than that and your liatris may not have a chance to really do well. If you are starting your liatris indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Havre is just an average the actual date of last frost is different every year. Half of the time in Havre last frost occurs after May 15 so just be sure to be ready to protect your liatris in the event of a surprise 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.