When to Plant Thunbergia in Zone 3a

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.

You can estimate when it's the best time to plant thunbergia in Zone 3a by checking out 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.

Thunbergia are not cold tolerant which means that it is necessary to wait until it warms up after the last frost before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant thunbergia
Possibly ok, but a risky time to plant thunbergia
Probably not a good time to plant thunbergia

The earliest that you can plant thunbergia in Zone 3a 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. Any later than that and your thunbergia may not have a chance to really do well. If you are starting your thunbergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 3a. In the coldest months of winter you can expect an average low temperature of -40°F.

Since the USDA zone info for Zone 3a is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 3a you get a frost after May 15 so always be ready to protect your thunbergia in the event of a surprise late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-40°F
Highest Expected Low-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.