The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant chrysocephalum is to consult the USDA zone info for Washington.

Planting Calendar for Chrysocephalum

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

It's probably a bad idea to plant chrysocephalum until after the last frost because they require warm weather.

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

The last month that you can plant chrysocephalum and expect a good harvest is probably August. Any later than that and your chrysocephalum may not have a chance to fully mature. Starting your chrysocephalum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Washington. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Washington is just an average the actual date of last frost will vary from year to year. Half of the time in Washington you get surprised by a frost after April 15 so just be sure to be ready to cover your chrysocephalum in the event of a late frost.

USDA Zone Info for Washington

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 Washington

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