One of the first steps you take when you are estimating 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.

It's possible to estimate when it's the best time to plant cerastium by reviewing the USDA zone info for Portland.

Planting Calendar for Cerastium

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

You can plant cerastium just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant cerastium in Portland is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant cerastium and expect a good harvest is probably October. If you wait any later than that and your cerastium may not have a chance to fully mature. If you are starting your cerastium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Portland. You should expect an average low temperature of 25°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Portland and it can change quite a bit from year to year. Since half of the time in Portland you get a frost after February 15 be ready to cover your cerastium in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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