Before planting it is a good idea to find your USDA Zone info to determine 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.

The USDA zone info for Allentown should be reffered to in order to figure out when it's possible to plant thunbergia.

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 tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant thunbergia in Allentown 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. Any later than that and your thunbergia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Allentown. In the coldest months of winter you should expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for Allentown is not always accurate and the actual date of last frost changes from year to year. Half of the time in Allentown last frost occurs after April 15 so always be ready to cover your thunbergia in the event of one of those late frosts.

USDA Zone Info for Allentown

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 Allentown

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