Before planting it is a good idea to find your USDA Zone info to determine 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 earliest that you can plant thunbergia in Berlin can be figured out by reviewing the USDA zone info.

Planting Calendar for Thunbergia

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

Thunbergia are not cold tolerant which means that you must 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 thunbergia 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 thunbergia and expect a good harvest is probably August. If you wait any later than that and your thunbergia may not have a chance to really do well. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

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

Since the USDA zone info for Berlin may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Berlin you get surprised by a frost after May 15 be ready to protect your thunbergia in the event of 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.