Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to estimate when it's a good idea to plant calliopsis by reviewing the USDA zone info for Green River.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Calliopsis do not do well in cold weather which tells us that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant calliopsis in Green River 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 calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to really do well. You can get started a little bit earlier by starting your calliopsis 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.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Green River and it will vary from year to year. Since half of the time in Green River you get surprised by a frost after May 15 be ready to cover your calliopsis if you have 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.