The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Potsdam you can determine when you can plant thunbergia by looking at the USDA zone info.

Planting Calendar for Thunbergia

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

Since thunbergia do not do well in cold weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant thunbergia 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 thunbergia and expect a good harvest is probably August. Any later than that and your thunbergia may not have a chance to fully mature. If you are starting your thunbergia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Potsdam. In the coldest months of winter you should 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 Potsdam and it will vary from year to year. Half of the time in Potsdam there is a last frost after May 15 so be sure to be ready to protect your thunbergia in the event of a surprise 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.