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

You can estimate when you can plant thunbergia in Lewiston by looking at the USDA zone info.

Planting Calendar for Thunbergia

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

Since thunbergia do not do well in cold weather you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant thunbergia in Lewiston 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. If you wait 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

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Lewiston and it will vary from year to year. Half of the time in Lewiston there is a last frost after April 15 so be sure to be ready to cover your thunbergia in the event of a late frost.

USDA Zone Info for Lewiston

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Lewiston

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