One of the best tools that you have as gardeners to help us estimate 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.

In South Portland you can determine when it's the best time to plant cerastium by referring to 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 tend to make it in mild cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cerastium in South Portland 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. Any later than that and your cerastium may not have a chance to fully mature. You can get started a little bit earlier by starting your cerastium indoors.

Last Frost Date

On average the last frost has passed is on April 15 in South Portland. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for South Portland is not always accurate the actual date of last frost changes from year to year. Half of the time in South Portland you get surprised by a frost after April 15 so be sure to be ready to protect your cerastium in the event of one of those late frosts.

USDA Zone Info for South Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in South Portland

You may be interested in your other planting guides for South Portland.