One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Winthrop Harbor you can determine when it's possible to plant thunbergia by reviewing the USDA zone info.

Planting Calendar for Thunbergia

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

Since thunbergia are not cold tolerant it's necessary 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 Winthrop Harbor 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 couple of weeks earlier by starting your thunbergia indoors.

Last Frost Date

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

Since the USDA zone info for Winthrop Harbor is not always accurate the actual date of last frost changes from year to year. Since half of the time in Winthrop Harbor you get a frost after April 15 be ready to cover your thunbergia if you have a surprise late frost.

USDA Zone Info for Winthrop Harbor

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 Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.