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.

The USDA zone info for Berlin can be reviewed to determine when to plant calliopsis.

Planting Calendar for Calliopsis

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

Since calliopsis are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant calliopsis in Berlin 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. Any later than that and your calliopsis may not have a chance to fully mature. Starting your calliopsis indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Berlin. You should expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Berlin may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Berlin you get surprised by a frost after May 15 so always be ready to protect your calliopsis if you have one of those late frosts.

USDA Zone Info for Berlin

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 Berlin

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