The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant hibiscus in Portsmouth should be estimated by referring to the USDA zone info.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since hibiscus are not cold tolerant you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant 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 hibiscus and expect a good harvest is probably August. Any later than that and your hibiscus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your hibiscus indoors.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Portsmouth is not always accurate and the actual date of last frost is different every year. Since half of the time in Portsmouth you get a frost after April 15 be ready to protect your hibiscus if you have one of those late frosts.

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.