When to Plant Tropical Hibiscus in Portsmouth, NH

One of the first steps you take when you are figuring out 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.

A common way of making a decision about when it's a good idea to plant tropical hibiscus is to refer to the USDA zone info for Portsmouth.


Planting Calendar for Tropical Hibiscus

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

Tropical Hibiscus are not cold tolerant which means that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

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

The earliest that you can plant tropical hibiscus 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 tropical hibiscus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tropical hibiscus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your tropical hibiscus indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Portsmouth. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Portsmouth is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Portsmouth it frosts late in the year after April 15 so make sure that you are ready to cover your tropical hibiscus if you have a 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.