One of the first steps you take when you are determining 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.

The USDA zone info for Kennewick can be used to figure out when you can plant thunbergia.

Planting Calendar for Thunbergia

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

It's not a good idea to plant thunbergia until after the last frost because they do not do well in cold weather.

The earliest that you can plant thunbergia in Kennewick 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. Starting your thunbergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Kennewick the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Keep in mind that USDA zone info for Kennewick is an average and the actual date of last frost will vary from year to year. Since half of the time in Kennewick there is a last frost after April 15 be ready to cover your thunbergia in the event of a late frost.

USDA Zone Info for Kennewick

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Kennewick

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