One of the first steps you take when you are determining 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 best time to plant calliopsis in Portsmouth should be determined by looking at the USDA zone info.

Planting Calendar for Calliopsis

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

Since calliopsis require warm weather you really should wait until after the last frost before you can plant them.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to really do well. If you are starting your calliopsis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Portsmouth. It might get as low as 10°F during 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 can change quite a bit from year to year. Half of the time in Portsmouth you get a frost after March 15 so always be ready to protect your calliopsis 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.