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 USDA zone info for Smithfield can be read to figure out when it's the best time to plant thunbergia.

Planting Calendar for Thunbergia

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

You can not plant thunbergia until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant thunbergia in Smithfield is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant thunbergia and expect a good harvest is probably August. 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 few weeks earlier.

Last Frost Date

In Smithfield the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 10°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Smithfield and it can change quite a bit from year to year. Since half of the time in Smithfield there is a last frost after March 15 be ready to protect your thunbergia if you have one of those late frosts.

USDA Zone Info for Smithfield

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Smithfield

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