When to Plant Coreopsis in Portland, OR

The USDA Zone info is a great tool for gardeners to help us determine 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 a good idea to figure out when it's a good idea to plant coreopsis by checking out 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.

Coreopsis do well in moderate cold which means that you can plant them earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant coreopsis
Possibly ok, but a risky time to plant coreopsis
Probably not a good time to plant coreopsis

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

The last month that you can plant coreopsis and expect a good harvest is probably September. Any later than that and your coreopsis may not have a chance to really do well. If you are starting your coreopsis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Portland the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portland and it changes from year to year. Half of the time in Portland you get surprised by a frost after March 15 so make sure that you are prepared to cover your coreopsis in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Portland

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