One of the first steps you take when you are getting a good idea 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.

One way of figuring out when it's the best time to plant coreopsis is to consult the USDA zone info for Walla Walla.

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.

The earliest that you can plant coreopsis in Walla Walla 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 grow to maturity. You can get started a couple of weeks earlier by starting your coreopsis indoors.

Last Frost Date

In Walla Walla the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Walla Walla and it will vary from year to year. Since half of the time in Walla Walla last frost occurs after April 15 be ready to protect your coreopsis in the event of one of those late frosts.

USDA Zone Info for Walla Walla

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Walla Walla

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