The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Worcester it's possible 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 the last frost has passed.

It's probably a bad idea to plant thunbergia until after all chance of frost has passed because they require warm weather.

The earliest that you can plant thunbergia in Worcester 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. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

The average date of last frost is April 15 in Worcester. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Worcester is an average the actual date of last frost will vary from year to year. Half of the time in Worcester you get surprised by a frost after April 15 so make sure that you are prepared to cover your thunbergia in the event of a surprise late frost.

USDA Zone Info for Worcester

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Worcester

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