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

One way of estimating when it's possible to plant thunbergia is to look at the USDA zone info for San Jose.

Planting Calendar for Thunbergia

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

Thunbergia are not cold tolerant which means that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant thunbergia in San Jose is March. However, you really should wait until April 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. If you wait any later than that and your thunbergia may not have a chance to grow to maturity. 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 San Jose the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Remember that USDA zone info for San Jose is an average and the actual date of last frost will vary from year to year. Since half of the time in San Jose there is a last frost after February 15 be ready to cover your thunbergia if you have a late frost.

USDA Zone Info for San Jose

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in San Jose

You may be interested in your other planting guides for San Jose.