When to Plant Coreopsis in Washington, IL

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when to plant coreopsis is to refer to the USDA zone info for Washington.


Planting Calendar for Coreopsis

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

You can plant coreopsis a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

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 Washington 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. You can get started a few weeks earlier by starting your coreopsis indoors.

Last Frost Date

In Washington the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Remember that USDA zone info for Washington is just an average and the actual date of last frost will vary from year to year. Since half of the time in Washington it frosts late in the year after April 15 be ready to cover your coreopsis if you have one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Washington

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