One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. 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 tropical hibiscus in Portsmouth can be figured out by referring to the USDA zone info.

Planting Calendar for Tropical Hibiscus

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

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

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. Any later than that and your tropical hibiscus may not have a chance to grow to maturity. Starting your tropical hibiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portsmouth and it will vary from year to year. Since half of the time in Portsmouth there is a last frost after April 15 be ready to cover your tropical hibiscus if you have a late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Portsmouth

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