Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portsmouth you can figure out when it's possible to plant cerastium by using the USDA zone info.

Planting Calendar for Cerastium

Frost tolerance for cerastium:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Cerastium do well in moderate cold which tells us that you can get them planted earlier than more sensitive plants.

The earliest that you can plant cerastium 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 cerastium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your cerastium may not have a chance to grow to maturity. If you are starting your cerastium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Portsmouth. It might get as low as 10°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. Half of the time in Portsmouth there is a last frost after March 15 so make sure that you are prepared to protect your cerastium if you have one of those late frosts.

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.