One of the best tools that you have as gardeners to help us estimate 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 first chance to plant thunbergia in Tucson can be determined by referring to the USDA zone info.

Planting Calendar for Thunbergia

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

Since thunbergia are not cold tolerant it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Tucson 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. Starting your thunbergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Tucson. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Tucson is an average and the actual date of last frost is different every year. Half of the time in Tucson there is a last frost after February 15 so always be ready to cover your thunbergia in the event of a surprise late frost.

USDA Zone Info for Tucson

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 Tucson

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