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

The earliest that you can plant thunbergia in Happy Valley 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 when the weather gets warmer.

Since thunbergia require warm weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant thunbergia in Happy Valley 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 fully mature. 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

The average date of last frost is March 15 in Happy Valley. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Happy Valley is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Happy Valley you get surprised by a frost after March 15 be ready to protect your thunbergia if you have a surprise late frost.

USDA Zone Info for Happy Valley

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 Happy Valley

You may be interested in your other planting guides for Happy Valley.