The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Portland you can estimate when to plant cerastium by checking out 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 a little bit of cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cerastium in 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 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

On average the last frost when the weather gets warmer is on April 15 in Portland. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Portland you get a frost after April 15 so always be ready to cover your cerastium in the event of a late frost.

USDA Zone Info for 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 Portland

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