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.

The earliest that you can plant thunbergia in Calistoga should be estimated by checking out the USDA zone info.

Planting Calendar for Thunbergia

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

Thunbergia are not cold tolerant which means that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Calistoga 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. You probably don't want to wait any later than that or else your thunbergia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your thunbergia indoors.

Last Frost Date

In Calistoga the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Calistoga is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Calistoga it frosts late in the year after February 15 so make sure that you are ready to cover your thunbergia if you have a late frost.

USDA Zone Info for Calistoga

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 Calistoga

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