Before planting it is a good idea to find your USDA Zone info to determine 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 determining when it's the best time to plant thunbergia is to check out the USDA zone info for Carlsbad.

Planting Calendar for Thunbergia

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

Since thunbergia require warm weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

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

In Carlsbad the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Carlsbad is just an average the actual date of last frost changes from year to year. Half of the time in Carlsbad last frost occurs after January 31 so make sure that you are prepared to cover your thunbergia in the event of one of those late frosts.

USDA Zone Info for Carlsbad

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 Carlsbad

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