Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when it's the best time to plant thunbergia is to refer to the USDA zone info for Sierra Madre.

Planting Calendar for Thunbergia

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

It's probably a bad idea to plant thunbergia until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant thunbergia in Sierra Madre is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant thunbergia and expect a good harvest is probably September. 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 couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Sierra Madre. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Sierra Madre is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Sierra Madre last frost occurs after January 31 so make sure that you are ready to cover your thunbergia if you have a surprise late frost.

USDA Zone Info for Sierra Madre

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Sierra Madre

You may be interested in your other planting guides for Sierra Madre.