One of the first steps you take when you are determining 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.

You should be able to estimate when it's possible to plant achillea by reviewing the USDA zone info for Umatilla.

Planting Calendar for Achillea

Frost tolerance for achillea:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Achillea do well in cold which means that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant achillea in Umatilla 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 achillea and expect a good harvest is probably September. Any later than that and your achillea may not have a chance to grow to maturity. Starting your achillea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Umatilla. It might get as low as 5°F during the coldest months of winter.

Keep in mind that USDA zone info for Umatilla is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Umatilla you get surprised by a frost after April 15 be ready to protect your achillea if you have one of those late frosts.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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