When to Plant Thunbergia in Portsmouth, NH

Before planting it is a good idea to find your USDA Zone info to figure out your garden 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 Portsmouth should be figured out 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.

You should not plant thunbergia until after all chance of frost has passed because they do not do well in cold weather.

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 Portsmouth 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 grow to maturity. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Portsmouth. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Portsmouth and it can change quite a bit from year to year. Since half of the time in Portsmouth it frosts late in the year after April 15 be ready to cover your thunbergia in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Portsmouth

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