One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant thunbergia is to examine the USDA zone info for Centralia.

Planting Calendar for Thunbergia

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

You can not plant thunbergia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant thunbergia in Centralia 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 fully mature. 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

In Centralia the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Keep in mind that USDA zone info for Centralia is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Centralia there is a last frost after March 15 so always be ready to cover your thunbergia in the event of a surprise late frost.

USDA Zone Info for Centralia

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Centralia

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