Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant thunbergia in Vernal by checking out the USDA zone info.

Planting Calendar for Thunbergia

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

Thunbergia are not cold tolerant which means that you really should 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 Vernal 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. Starting your thunbergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Vernal. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Vernal is not always accurate the actual date of last frost changes from year to year. Half of the time in Vernal you get a frost after April 15 so be sure to be ready to protect your thunbergia in the event of a late frost.

USDA Zone Info for Vernal

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 Vernal

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