Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to determine when it's the best time to plant thunbergia by looking at the USDA zone info for Irmo.

Planting Calendar for Thunbergia

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

Since thunbergia are not cold tolerant it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant thunbergia in Irmo 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. If you are starting your thunbergia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Irmo. You should expect an average low temperature of 10°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Irmo and it changes from year to year. Half of the time in Irmo last frost occurs after March 15 so just be sure to be ready to cover your thunbergia if you have a surprise late frost.

USDA Zone Info for Irmo

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 Irmo

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