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

The USDA zone info for Mount Washington can be reffered to in order to estimate when it's the best time to plant thunbergia.

Planting Calendar for Thunbergia

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

You really shouldn't plant thunbergia until after the last frost because they do not do well in cold weather.

The earliest that you can plant thunbergia in Mount Washington 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 really do well. Starting your thunbergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Mount Washington may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Mount Washington you get a frost after April 15 so make sure that you are prepared to cover your thunbergia if you have a surprise late frost.

USDA Zone Info for Mount Washington

Here is the info for USDA Zone 6b.

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

Plants to Grow in Mount Washington

You may be interested in your other planting guides for Mount Washington.