Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant thunbergia in Powell by checking out 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.

Since thunbergia are not cold tolerant you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant thunbergia in Powell 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. 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

In Powell 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.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Powell and it will vary from year to year. Since half of the time in Powell you get surprised by a frost after May 15 be ready to protect your thunbergia in the event of a surprise late frost.

USDA Zone Info for Powell

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 Powell

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