One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when it's possible to plant thunbergia by checking out the USDA zone info for Salem.

Planting Calendar for Thunbergia

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

Thunbergia do not do well in cold weather which tells us that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Salem 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. You probably don't want to wait any later than that or else your thunbergia may not have a chance to really do well. You can get started a few weeks earlier by starting your thunbergia indoors.

Last Frost Date

On average the last frost is on March 15 in Salem. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Salem is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Salem last frost occurs after March 15 be ready to cover your thunbergia if you have a surprise late frost.

USDA Zone Info for Salem

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Salem

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