One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant thunbergia in Barstow can 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 tells us that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant thunbergia in Barstow 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 grow to maturity. You can get started a few weeks earlier by starting your thunbergia indoors.

Last Frost Date

In Barstow the average date of last frost happens on February 15. You should expect an average low temperature of 20°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Barstow and it is different every year. Since half of the time in Barstow you get a frost after February 15 be ready to cover your thunbergia if you have a late frost.

USDA Zone Info for Barstow

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 Barstow

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