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

By reviewing the USDA zone info for Highland Park you will be able to figure out when it's possible to plant thunbergia.

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 it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant thunbergia in Highland Park 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. If you wait any later than that and your thunbergia may not have a chance to fully mature. Starting your thunbergia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Highland Park. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Highland Park and it changes from year to year. Half of the time in Highland Park last frost occurs after April 15 so make sure that you are prepared to cover your thunbergia in the event of one of those late frosts.

USDA Zone Info for Highland Park

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Highland Park

You may be interested in your other planting guides for Highland Park.