The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when it's possible to plant thunbergia is to consult the USDA zone info for Princeton.

Planting Calendar for Thunbergia

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

Thunbergia do not do well in cold weather which means that it is 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 Princeton 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 grow to maturity. If you are starting your thunbergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Princeton. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Princeton may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Princeton last frost occurs after April 15 so always be ready to cover your thunbergia if you have one of those late frosts.

USDA Zone Info for Princeton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Princeton

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