The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant thunbergia in Troutdale should be determined by referring to the USDA zone info.

Planting Calendar for Thunbergia

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

You should not plant thunbergia until after the last frost has passed because they require warm weather.

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

Last Frost Date

On average all chance of frost has passed is on March 15 in Troutdale. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Troutdale is an average the actual date of last frost changes from year to year. Half of the time in Troutdale you get a frost after March 15 so be sure to be ready to protect your thunbergia if you have a surprise late frost.

USDA Zone Info for Troutdale

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 Troutdale

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