One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Douglas you will be able to estimate when to plant thunbergia.

Planting Calendar for Thunbergia

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

Thunbergia do not do well in cold weather which tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant thunbergia in Douglas 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. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

In Douglas 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.

Always keep in mind that USDA zone info for Douglas is not always accurate and the actual date of last frost is different every year. Since half of the time in Douglas there is a last frost after March 15 be ready to protect your thunbergia if you have one of those late frosts.

USDA Zone Info for Douglas

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 Douglas

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