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

The USDA zone info for Oregon should be reffered to in order to figure out when it's possible to plant calliopsis.

Planting Calendar for Calliopsis

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

You can not plant calliopsis until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to fully mature. Starting your calliopsis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Oregon. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Oregon is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Oregon last frost occurs after April 15 be ready to cover your calliopsis 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.