The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Oak Harbor you can determine when it's the best time to plant thunbergia by using 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.

Thunbergia are not cold tolerant which means that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant thunbergia in Oak 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. You probably don't want to wait any later than that or else your thunbergia may not have a chance to really do well. If you are starting your thunbergia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Oak Harbor the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Oak Harbor is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Oak Harbor there is a last frost after March 15 be ready to cover your thunbergia if you have a late frost.

USDA Zone Info for Oak Harbor

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Oak Harbor

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