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

A way of estimating when you can plant thunbergia is to check out the USDA zone info for Edwardsville.

Planting Calendar for Thunbergia

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

Since thunbergia are not cold tolerant you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Edwardsville 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. If you are starting your thunbergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Edwardsville. You can expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Edwardsville and it will vary from year to year. Since half of the time in Edwardsville there is a last frost after April 15 be ready to protect your thunbergia if you have a surprise late frost.

USDA Zone Info for Edwardsville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Edwardsville

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