Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Oregon it's possible to estimate when it's possible to plant chrysocephalum.

Planting Calendar for Chrysocephalum

Frost tolerance for chrysocephalum:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant chrysocephalum until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant chrysocephalum in Oregon 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. If you wait any later than that and your chrysocephalum may not have a chance to grow to maturity. If you are starting your chrysocephalum 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 April 15 in Oregon. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Oregon may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Oregon there is a last frost after April 15 be ready to cover your chrysocephalum if you have one of those late frosts.

USDA Zone Info for Oregon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oregon

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