One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when to plant trachelium by checking out the USDA zone info for Portsmouth.

Planting Calendar for Trachelium

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

You really shouldn't plant trachelium until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant trachelium 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 trachelium and expect a good harvest is probably August. Any later than that and your trachelium may not have a chance to fully mature. Starting your trachelium indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Portsmouth is just an average the actual date of last frost will vary 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 trachelium 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.