One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant liatris in Portsmouth by reviewing the USDA zone info.

Planting Calendar for Liatris

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

Liatris are very cold tolerant which means that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant liatris 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 liatris and expect a good harvest is probably September. Any later than that and your liatris may not have a chance to really do well. Starting your liatris indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Portsmouth. In the coldest months of winter you can expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Portsmouth is just an average and the actual date of last frost is different every year. Since half of the time in Portsmouth you get surprised by a frost after April 15 be ready to cover your liatris in the event of 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.