One of the best tools that you have as gardeners to help us determine 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 Portland you can figure out when it's a good idea to plant chrysocephalum by reviewing the USDA zone info.

Planting Calendar for Chrysocephalum

Frost tolerance for chrysocephalum:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Chrysocephalum are not cold tolerant which means that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

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

The last month that you can plant chrysocephalum and expect a good harvest is probably September. Any later than that and your chrysocephalum may not have a chance to really do well. You can get started a little bit earlier by starting your chrysocephalum indoors.

Last Frost Date

In Portland the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Portland and it changes from year to year. Since half of the time in Portland you get a frost after February 15 be ready to cover your chrysocephalum if you have a 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.