When to Plant Coreopsis in Mill Creek, WA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 Mill Creek should be read to estimate when it's the best time to plant coreopsis.


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 little bit earlier in the year because they are moderately cold tolerant.

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 Mill Creek 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 fully mature. If you are starting your coreopsis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Mill Creek. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Mill Creek is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Mill Creek you get surprised by a frost after March 15 so make sure that you are ready to cover your coreopsis if you have one of those late frosts.

USDA Zone Info for Mill Creek

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 Mill Creek

You may be interested in your other planting guides for Mill Creek.