One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's a good idea to plant thunbergia is to look at the USDA zone info for La Crosse.

Planting Calendar for Thunbergia

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

It's a bad idea to plant thunbergia until after all chance of frost has passed because they require warm weather.

The earliest that you can plant thunbergia in La Crosse 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. You probably don't want to wait any later than that or else 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

The average date of last frost is May 15 in La Crosse. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for La Crosse is just an average the actual date of last frost changes from year to year. Since half of the time in La Crosse it frosts late in the year after May 15 be ready to cover your thunbergia if you have one of those late frosts.

USDA Zone Info for La Crosse

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 La Crosse

You may be interested in your other planting guides for La Crosse.