One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant coreopsis in Tualatin by referring to the USDA zone info.

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.

The earliest that you can plant coreopsis in Tualatin 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. 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 few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Tualatin is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Tualatin it frosts late in the year after March 15 so always be ready to protect your coreopsis in the event of a late frost.

USDA Zone Info for Tualatin

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 Low	15°F
Highest Expected Low	20°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 Tualatin

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