One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant thunbergia is to look at the USDA zone info for Alvin.

Planting Calendar for Thunbergia

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

Since thunbergia require warm weather it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant thunbergia in Alvin 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 fully mature. You can get started a couple of weeks earlier by starting your thunbergia indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Alvin. You should expect an average low temperature of 20°F in the coldest months of winter.

It's important to remember that USDA zone info for Alvin may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Alvin you get a frost after February 15 be ready to protect your thunbergia in the event of a surprise late frost.

USDA Zone Info for Alvin

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 Alvin

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