The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when to plant coreopsis by looking at the USDA zone info for Portland.

Planting Calendar for Coreopsis

Frost tolerance for coreopsis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since coreopsis are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

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

The last month that you can plant coreopsis and expect a good harvest is probably October. You probably don't want to wait any later than that or else your coreopsis may not have a chance to fully mature. If you are starting your coreopsis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Portland. In the coldest months of winter you should expect an average low temperature of 25°F.

Just be sure to remember that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Portland there is a last frost after February 15 be ready to protect your coreopsis in the event of one of those late frosts.

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.