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

In Spencer you can figure out when it's the best time to plant thunbergia by referring to the USDA zone info.

Planting Calendar for Thunbergia

Frost tolerance for thunbergia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since thunbergia require warm weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant thunbergia in Spencer 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

The average date of last frost is April 15 in Spencer. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Spencer is an average the actual date of last frost changes from year to year. Since half of the time in Spencer last frost occurs after April 15 be ready to cover your thunbergia if you have a late frost.

USDA Zone Info for Spencer

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

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

Plants to Grow in Spencer

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