One of the first steps you take when you are getting a good idea 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.

A common way of determining when it's the best time to plant liatris is to use the USDA zone info for Green River.

Planting Calendar for Liatris

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

You can plant liatris earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant liatris in Green River 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 grow to maturity. You can get started a couple of weeks earlier by starting your liatris indoors.

Last Frost Date

In Green River the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Green River is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Green River it frosts late in the year after May 15 so always be ready to cover your liatris in the event of one of those late frosts.

USDA Zone Info for Green River

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 Green River

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