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 estimate when it's the best time to plant calliopsis by looking at the USDA zone info.

Planting Calendar for Calliopsis

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

You should not plant calliopsis until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant calliopsis in Portland 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. You probably don't want to wait any later than that or else your calliopsis may not have a chance to fully mature. You can get started a little bit earlier by starting your calliopsis indoors.

Last Frost Date

The average date of last frost is April 15 in Portland. In the coldest months of winter you should expect an average low temperature of 0°F.

Remember that USDA zone info for Portland is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Portland you get a frost after April 15 be ready to protect your calliopsis in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Portland

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