The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant hardy hibiscus in Portsmouth should be figured out by checking out the USDA zone info.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus do well in cold which means that you can plant them a quite a bit earlier than other frost tender plants.

The earliest that you can plant hardy hibiscus in Portsmouth is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to fully mature. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Portsmouth the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just 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 there is a last frost after March 15 be ready to protect your hardy hibiscus if you have a late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Portsmouth

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