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

You can figure out when it's the best time to plant thunbergia in River Rouge 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.

Thunbergia do not do well in cold weather which tells us that you must 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 River Rouge 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 few weeks earlier by starting your thunbergia indoors.

Last Frost Date

The average date of last frost is April 15 in River Rouge. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for River Rouge is an average and the actual date of last frost is different every year. Half of the time in River Rouge you get a frost after April 15 so make sure that you are ready to protect your thunbergia in the event of a surprise late frost.

USDA Zone Info for River Rouge

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 River Rouge

You may be interested in your other planting guides for River Rouge.