The USDA Zone info is a great tool for gardeners to help us figure out 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.

It's a good idea to determine when it's the best time to plant calliopsis by reviewing the USDA zone info for Potsdam.

Planting Calendar for Calliopsis

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

Since calliopsis do not do well in cold weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant calliopsis in Potsdam 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 fully mature. You can get started a little bit earlier by starting your calliopsis indoors.

Last Frost Date

In Potsdam the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Potsdam and it is different every year. Half of the time in Potsdam you get surprised by a frost after May 15 so just be sure to be ready to cover your calliopsis in the event of a late frost.

USDA Zone Info for Potsdam

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 Potsdam

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