Before planting it is a good idea to find your USDA Zone info to figure out 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.

You will be able to figure out when it's a good idea to plant thunbergia by using the USDA zone info for Ballwin.

Planting Calendar for Thunbergia

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

Thunbergia are not cold tolerant which tells us that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Ballwin is April. However, you really should wait until May 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 really do well. Starting your thunbergia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ballwin. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Ballwin is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Ballwin there is a last frost after April 15 so always be ready to protect your thunbergia if you have a late frost.

USDA Zone Info for Ballwin

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ballwin

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