One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 Anchorage can be determined by reviewing the USDA zone info.

Planting Calendar for Thunbergia

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

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

The earliest that you can plant thunbergia in Anchorage is May. However, you really should wait until June 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 fully mature. You can get started a couple of weeks earlier by starting your thunbergia indoors.

Last Frost Date

In Anchorage the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Anchorage may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Anchorage there is a last frost after May 15 be ready to cover your thunbergia if you have one of those late frosts.

USDA Zone Info for Anchorage

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Anchorage

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