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

A common way of getting a good idea when it's a good idea to plant thunbergia is to refer to the USDA zone info for Ukiah.

Planting Calendar for Thunbergia

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

You really shouldn't plant thunbergia until after the last frost because they are not cold tolerant.

The earliest that you can plant thunbergia in Ukiah 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. Any later than that and your thunbergia may not have a chance to really do well. Starting your thunbergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Ukiah the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Ukiah is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Ukiah last frost occurs after February 15 be ready to protect your thunbergia in the event of a surprise late frost.

USDA Zone Info for Ukiah

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Ukiah

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