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

The USDA zone info for Rancho Cucamonga should be reviewed to figure out when you can 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 are not cold tolerant you must wait until after the last frost before you can plant them.

The earliest that you can plant thunbergia in Rancho Cucamonga 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. You can get started a few weeks earlier by starting your thunbergia indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Rancho Cucamonga. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Rancho Cucamonga is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Rancho Cucamonga you get surprised by a frost after February 15 so be sure to be ready to protect your thunbergia in the event of one of those late frosts.

USDA Zone Info for Rancho Cucamonga

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 Rancho Cucamonga

You may be interested in your other planting guides for Rancho Cucamonga.